ES2813364T3 - Process for removing sulfur compounds from hydrocarbons - Google Patents

Abstract

Process for reducing the sulfur content of a hydrocarbon material containing sulfur compounds, the process comprising: a) contacting the hydrocarbon material with one or more primary oxidants to provide a primary oxidized hydrocarbon material such that the oxidant primary oxidizes sulfur compounds to sulfoxide and/or sulfone compounds, wherein the primary oxidant is selected from one or more of the group consisting of N-chloroimide, hypobromous acid, electrolyzed oxidizing water, and catalyzed and cocatalyzed hydrogen peroxide; and b) contacting the primary oxidized hydrocarbon material with a secondary oxidant to provide a secondary oxidized hydrocarbon material, wherein the secondary oxidant is selected from one or more of the group consisting of hydroxyl radicals, liquid ferrate (iron VI ), chlorine dioxide and hypofluorous acid/polar liquid solvent, such that the secondary oxidant oxidizes sulfur compounds to sulfoxide and/or sulfone compounds; and c) contacting the primary and secondary oxidized hydrocarbon material with an extractant to allow at least a portion of the sulfoxide and/or sulfone compounds to extract into the extractant to provide a stream of sulfoxide and/or or sulfone and a low sulfur hydrocarbon stream; and d) contacting the sulfoxide and/or sulfone stream with a tertiary oxidant to provide an aqueous sulfite stream and a low sulfur aromatic hydrocarbon stream, wherein the tertiary oxidant oxidizes sulfone and/or sulfoxide compounds to compounds sulfite; and e) separating the sulfoxide and/or sulfone stream from the low sulfur hydrocarbon stream, and when the primary oxidant is catalyzed and cocatalyzed hydrogen peroxide, it is hydrogen peroxide catalyzed by homogeneous or heterogeneous catalysts.

Description

DESCRIPTION

Process for removing sulfur compounds from hydrocarbons

Countryside

[0001] The present invention relates to the removal of sulfur compounds from hydrocarbon streams.

Background

[0002] The removal of sulfur compounds from fossil hydrocarbon (HC) streams, such as natural gas condensate, kerosene, turbine jet fuel, diesel and fuel oil, reducing them to ultra-low ppm levels is of notable technical importance in the industry and society due to the fact that sulfur-containing compounds can have negative effects on technical operations and the environment. For example, the presence of chemically bound sulfur, such as organosulfur compounds, in hydrocarbon streams can cause corrosion of engine parts and processing equipment. Furthermore, the emission of SOx and NOx (oxides of nitrogen and sulfur) by the combustion of fossil fuels that contain sulfur and nitrogen, causes damage to the environment. It is of concern in the presence of sulfur from Poly-Nuclear Aromatics (PAH), which when burned can produce toxic and probable carcinogens in the environment.

[0003] With an increasing emphasis on eliminating or minimizing the discharge of sulfur to the atmosphere, attention has been focused on the removal of sulfur and nitrogen compounds from hydrocarbon feedstocks before said hydrocarbons are combusted. The desulfurization of raw materials is required in most countries of the world. Currently, legislation in the United States limits the level of sulfur in fuels, such as hydrocarbons in gasoline and diesel, to 30 ppm and 15 ppm respectively. This 15 ppm limit is stricter in other parts of the world, such as the EU, where allowable sulfur levels are as low as <10 ppm. Likewise, this is also the mandatory level adopted by other countries, such as Japan, Australia and New Zealand. US 2007/0051667 A1 discloses the reduction of the content, including sulfur, of diesel fuel, which is achieved by oxidation in the presence of a catalyst followed by a liquid-liquid countercurrent extraction.

US 2009/0065399 A1 relates to an improved method for desulfurizing a fuel stream, such as a gas oil stream, including generation of a sulfone oil, desulfurization of sulfone oil, and recycling of the rich stream. biphenyl and the resulting ultra-low sulfur diesel streams. US 2012/0018350 A1 discloses the desulfurization of fossil fuels by combining fossil fuels with an aqueous mixture of ozone or hydrogen peroxide and a tetraoctylphosphonium salt phase transfer catalyst, and the mixture is then subjected to reactive mixing to form oxidized sulfur compounds in fuel.

Document US 2002/0148756 A1 discloses a process for the production of components for the refinery mixing of transport fuels by selective oxidation of feedstock comprising a mixture of hydrocarbons, and organic sulfur-containing and nitrogen-containing compounds .

Document US 2007/0227950 A1 discloses a process for the production of components for the refinery mixing of transport fuels by selective oxidation of feedstock comprising a mixture of hydrocarbons, and organic sulfur-containing and nitrogen-containing compounds .

Summary

[0004] The present disclosure relates generally to a process for reducing the sulfur content of hydrocarbon feedstocks, such as natural gas condensate, kerosene, jet turbine fuel, diesel, vacuum gas oil and fuel oil. In some embodiments, the discussion refers to a process for removing a range of sulfur compounds from hydrocarbon material that contains a range of sulfur compounds.

[0005] The present invention and its scope are defined by the appended claims. The more generic description of the invention is provided for illustrative purposes only. Embodiments not covered by these claims are for reference purposes only.

[0006] The process disclosed herein uses a custom oxidation process comprising one or two oxidation steps to produce the corresponding oxidized sulfur compounds in the form of sulfoxides and / or sulfones. These sulfoxides and sulfones, although still present in liquid hydrocarbon streams, are subsequently extracted, thus producing a low sulfur hydrocarbon stream and, optionally, after further treatment of the sulfoxides and / or sulfones, they produce a low sulfur aromatic hydrocarbon stream and an aqueous sodium sulfite or sulfuric acid stream. The low sulfur hydrocarbon stream and the low sulfur aromatic hydrocarbon stream can be recycled individually or they can be combined for recycling. In some embodiments, ultra-low-sulfur hydrocarbon and ultra-low-sulfur aromatic hydrocarbon streams are produced.

[0007] Accordingly, in at least one preferred embodiment, the process of the present invention advantageously provides an economically viable way of reducing sulfur levels in liquid hydrocarbons containing a variety of sulfur species to produce recyclable hydrocarbon streams, waste streams. very low and minimal loss of hydrocarbon components.

[0008] In a first aspect, a process is provided for reducing the sulfur content of a hydrocarbon material containing sulfur compounds, the process comprising:

a) contacting the hydrocarbon material with one or more primary oxidants to oxidize sulfur compounds to sulfoxide and / or sulfone compounds to provide a primary oxidized hydrocarbon material, wherein the primary oxidants have a ORP up to about 1550 mV;

b) contacting the primary oxidized hydrocarbon material with a secondary oxidant to oxidize sulfur compounds not oxidized by the primary oxidant to sulfoxide and / or sulfone compounds in order to provide a secondary oxidized hydrocarbon material, wherein the secondary oxidant has an ORP greater than about 1550 mV;

c) contacting the primary and / or secondary oxidized hydrocarbon material with an extractant to allow at least a portion of the sulfoxide and / or sulfone compounds to be extracted into the extractant in order to provide a sulfoxide stream and / or sulfone and a low sulfur hydrocarbon stream; Y

d) contacting the sulfoxide and / or sulfone stream with a tertiary oxidant to provide an aqueous sulfite stream and a low-sulfur aromatic hydrocarbon stream, wherein the tertiary oxidant oxidizes sulfone and / or sulfoxide compounds to compounds sulfite.

[0009] In accordance with the invention claimed herein, the primary oxidant is selected from one or more of the group consisting of:

a) N-chloroimide,

b) hypobromous acid

d) electrolyzed oxidizing water and

e) catalyzed and cocatalyzed hydrogen peroxide.

[0010] The catalyzed and cocatalyzed hydrogen peroxide can be hydrogen peroxide catalyzed by homogeneous or heterogeneous catalysts, including catalysts selected from the group that includes, but is not limited to, transition metals, noble metals, and rate control catalysts. degradation; and cocatalyzed by a Phase Transfer Catalyst (PTC).

[0011] Degradation rate control catalysts include, but are not limited to, phosphotungstic acid (PTA). Phosphotungstic acid can be formed from sodium tungstate dihydrate (Na2WO4.2H2O) and phosphoric acid.

[0012] In one embodiment, the catalyst is a heterogeneous catalyst, such as "Oxy-catalyst" produced by Hydrogen Link, Inc.

[0013] PTC can be selected from the group including, but not limited to: quaternary ammonium salts including, but not limited to: quaternary ammonium hydrogen sulfates, such as tri-C8-10-alkylmethyl, hydrogen sulfates (eg Ultra C, which is a proprietary PTC available in and developed by Ultraclean Fuel and PTC Organics); methyltrialkyl (C8-C1ü) ammonium chloride (for example Adogen® 464 available from Evonik Industries); and N-methyl-N, N-dioctyloctane-1-ammonium salts such as chloride (eg Aliquat® 336 available from BASF); or equivalent PTC's known to those skilled in the art.

[0014] In one embodiment, the primary oxidant is catalyzed and cocatalyzed hydrogen peroxide wherein the catalyzed and cocatalyzed hydrogen peroxide is phosphotungstic acid catalyzed hydrogen peroxide (PTA) comprising dihydrated sodium tungstate and phosphoric acid and cocatalyzed with a phase transfer catalyst (PTC) comprising a quaternary ammonium hydrogen sulfate.

[0015] In accordance with the invention claimed herein, the secondary oxidant is selected from one or more of the group consisting of:

d) hydroxyl radicals,

e) liquid ferrate (iron VI),

f) chlorine dioxide and

g) hyperfluoro acid / polar solvent.

[0016] In still another embodiment, the hydrocarbon material containing sulfur compounds has a sulfur mass of> 1,000 ppm.

[0017] According to a second aspect, a process is provided for reducing the sulfur content of a hydrocarbon material containing sulfur compounds, the process comprising:

a) contacting the hydrocarbon material with one or more primary oxidants to provide a primary oxidized hydrocarbon material in which the primary oxidant is selected from one or more of the group consisting of N-chloroimide, hypobromous acid, oxidizing water electrolyzed and catalyzed and cocatalyzed hydrogen peroxide, such that the primary oxidant oxidizes sulfur compounds to sulfoxide and / or sulfone compounds;

me

b) contacting the hydrocarbon material or primary oxidized hydrocarbon material with a secondary oxidant to provide a secondary oxidized hydrocarbon material in which the secondary oxidant is selected from one or more of the group consisting of hydroxyl radicals, liquid ferrate (iron VI), chlorine dioxide and hyperfluorous acid / polar solvent, such that the secondary oxidant oxidizes sulfur compounds to sulfoxide and / or sulfone compounds;

Y

c) contacting the primary and / or secondary oxidized hydrocarbon material with an extractant to allow at least a portion of the sulfoxide and / or sulfone compounds to be extracted into the extractant to provide a stream of sulfoxide and / or sulfone and a low sulfur hydrocarbon stream;

Y

d) contacting the sulfoxide and / or sulfone stream with a tertiary oxidant to provide an aqueous sulfite stream and a low sulfur aromatic hydrocarbon stream,

wherein the tertiary oxidant oxidizes sulfone and / or sulfoxide compounds to sulfite compounds.

[0018] In an embodiment according to the second aspect, the catalyzed and cocatalyzed hydrogen peroxide can be hydrogen peroxide catalyzed by homogeneous or heterogeneous catalysts, including catalysts selected from the group that includes, but is not limited to, transition metals, noble metals and degradation rate control catalysts; and cocatalyzed by a phase transfer catalyst (PTC) as defined above.

[0019] In a preferred embodiment according to the second aspect, the catalyzed and cocatalyzed hydrogen peroxide is phosphotungstic acid catalyzed hydrogen peroxide (PTA) comprising sodium tungstate dihydrate and phosphoric acid and cocatalyzed by a phase transfer catalyst (PTC) comprising a quaternary ammonium salt, preferably a quaternary ammonium hydrogen sulfate.

[0020] In another embodiment according to the second aspect, the catalyzed and cocatalyzed hydrogen peroxide is hydrogen peroxide catalyzed by a heterogeneous catalyst, such as "Oxy-catalyst" (Hydrogen Link, Inc) and cocatalyzed by a transfer catalyst. phase (PTC).

[0021] In another embodiment of the second aspect, when the primary oxidant is catalyzed and cocatalyzed hydrogen peroxide as described above, the process includes steps a) and b).

[0022] In still another embodiment of the second aspect, when the primary oxidant is catalyzed and cocatalyzed hydrogen peroxide as described above, the process includes only step a).

[0023] An advantage of one embodiment of the process disclosed herein is its ability to reduce the sulfur content of a range of hydrocarbons containing a variety of sulfur compounds of varying complexity and oxidation resistance. An advantage of another embodiment of the process disclosed herein is the ability to carry out a two-step oxidation process to oxidize a range of sulfur-containing hydrocarbon compounds with varying resistance to oxidation. An advantage of yet another embodiment of the process disclosed herein is the ability to produce a low sulfur hydrocarbon stream and a low sulfur aromatic stream.

[0024] Accordingly, one embodiment of the first and second aspects provides a process for reducing the sulfur content of a hydrocarbon material containing sulfur compounds, the process comprising: a) contacting the hydrocarbon material with one or plus primary oxidants to provide a primary oxidized hydrocarbon material such that the primary oxidant oxidizes sulfur compounds to sulfoxide and / or sulfone compounds, wherein the primary oxidant is selected from one or more of the group consisting of N-chloroimide, hypobromous acid, electrolyzed oxidizing water, and catalyzed and cocatalyzed hydrogen peroxide, and wherein the catalyzed hydrogen peroxide and cocatalyzed is hydrogen peroxide catalyzed by phosphotungstic acid (PTA) and cocatalyzed by a phase transfer catalyst (PTC), preferably a quaternary ammonium salt, more preferably a quaternary ammonium hydrogen sulfate;

Y

b) contacting the primary oxidized hydrocarbon material with a secondary oxidant to provide a secondary oxidized hydrocarbon material in which the secondary oxidant is selected from one or more of the group consisting of hydroxyl radicals, liquid ferrate (iron VI) , chlorine dioxide and hyperfluorous acid / polar liquid solvent, such that the secondary oxidant oxidizes sulfur compounds to sulfoxide and / or sulfone compounds;

Y

c) contacting the primary and / or secondary oxidized hydrocarbon material with an extractant to allow at least a portion of the sulfoxide and / or sulfone compounds to be extracted into the extractant in order to provide a sulfoxide stream and / or sulfone and a low sulfur hydrocarbon stream;

Y

d) contacting the sulfoxide and / or sulfone stream with a tertiary oxidant to provide an aqueous sulfite stream and a low sulfur aromatic hydrocarbon stream,

wherein the tertiary oxidant oxidizes sulfone and / or sulfoxide compounds to sulfite compounds.

[0025] Another embodiment of the first and second aspects provides a process for reducing the sulfur content of a hydrocarbon material containing sulfur compounds, the process comprising:

a) contacting the hydrocarbon material with one or more primary oxidants to provide a primary oxidized hydrocarbon material such that the primary oxidant oxidizes sulfur compounds to sulfoxide and / or sulfone compounds, wherein the primary oxidant is catalyzed and cocatalyzed hydrogen peroxide and wherein the catalyzed and cocatalyzed hydrogen peroxide is hydrogen peroxide catalyzed by phosphotungstic acid and cocatalyzed with a phase transfer catalyst (PTC) comprising a quaternary ammonium salt, preferably an ammonium hydrogen sulfate quaternary;

Y

b) contacting the primary oxidized hydrocarbon material with a secondary oxidant to provide a secondary oxidized hydrocarbon material in which the secondary oxidant is selected from one or more of the group consisting of hydroxyl radicals, liquid ferrate (iron VI) , chlorine dioxide and hyperfluorous acid / polar liquid solvent, such that the secondary oxidant oxidizes sulfur compounds to sulfoxide and / or sulfone compounds;

Y

c) contacting the primary and / or secondary oxidized hydrocarbon material with an extractant to allow at least a portion of the sulfoxide and / or sulfone compounds to be extracted into the extractant in order to provide a sulfoxide stream and / or sulfone and a low sulfur hydrocarbon stream;

Y

d) contacting the sulfoxide and / or sulfone stream with a tertiary oxidant to provide an aqueous sulfite stream and a low sulfur aromatic hydrocarbon stream,

wherein the tertiary oxidant oxidizes sulfone and / or sulfoxide compounds to sulfite compounds.

[0026] Another embodiment of the first and second aspects provides a process for reducing the sulfur content of a hydrocarbon material containing sulfur compounds, the process comprising:

a) contacting the hydrocarbon material with one or more primary oxidants to provide a primary oxidized hydrocarbon material such that the primary oxidant oxidizes sulfur compounds to sulfoxide and / or sulfone compounds, wherein the primary oxidant is catalyzed and cocatalyzed hydrogen peroxide and wherein the catalyzed and cocatalyzed hydrogen peroxide is hydrogen peroxide catalyzed by a heterogeneous catalyst (eg "Oxy-Catalyst" from Hydrogen Link Inc) and cocatalyzed with a phase transfer catalyst (PTC ) comprising a quaternary ammonium salt, preferably a quaternary ammonium hydrogen sulfate;

Y

b) contacting the primary oxidized hydrocarbon material with a secondary oxidant to provide a secondary oxidized hydrocarbon material in which the secondary oxidant is selected from one or more of the group consisting of hydroxyl radicals, liquid ferrate (iron VI) , chlorine dioxide and hyperfluorous acid / polar liquid solvent, such that the secondary oxidant oxidizes sulfur compounds to sulfoxide and / or sulfone compounds;

Y

c) contacting the primary and / or secondary oxidized hydrocarbon material with an extractant to allow at least a portion of the sulfoxide and / or sulfone compounds to be extracted into the extractant in order to provide a sulfoxide stream and / or sulfone and a low sulfur hydrocarbon stream;

Y

d) contacting the sulfoxide and / or sulfone stream with a tertiary oxidant to provide an aqueous sulfite stream and a low sulfur aromatic hydrocarbon stream,

wherein the tertiary oxidant oxidizes sulfone and / or sulfoxide compounds to sulfite compounds.

In still another embodiment of the second aspect, a process is provided for reducing the sulfur content of a hydrocarbon material containing sulfur compounds, the process comprising the steps of:

a) contacting the hydrocarbon material with one or more primary oxidants to provide an oxidized primary hydrocarbon material such that the primary oxidant oxidizes sulfur compounds to sulfoxide and / or sulfone compounds, wherein the primary oxidant is catalyzed and cocatalyzed hydrogen peroxide and wherein the catalyzed and cocatalyzed hydrogen peroxide is hydrogen peroxide catalyzed by phosphotungstic acid and cocatalyzed with a phase transfer catalyst (PTC) comprising a quaternary ammonium salt, for example, a hydrogen sulfate of quaternary ammonium;

c) contacting the primary oxidized hydrocarbon material with an extractant to allow at least a portion of the sulfoxide and / or sulfone compounds to be extracted into the extractant in order to provide a sulfoxide and / or sulfone stream and a low sulfur hydrocarbon stream;

Y

d) contacting the sulfoxide and / or sulfone stream with a tertiary oxidant to provide an aqueous sulfite stream and a low-sulfur aromatic hydrocarbon stream, wherein the tertiary oxidant oxidizes sulfone and / or sulfoxide compounds to compounds sulfite.

In still another embodiment of the second aspect, a process is provided for reducing the sulfur content of a hydrocarbon material containing sulfur compounds, the process comprising the steps of:

a) contacting the hydrocarbon material with one or more primary oxidants to provide a primary oxidized hydrocarbon material such that the primary oxidant oxidizes sulfur compounds to sulfoxide and / or sulfone compounds, wherein the primary oxidant is peroxide catalyzed and cocatalyzed hydrogen peroxide and wherein the catalyzed and cocatalyzed hydrogen peroxide is hydrogen peroxide catalyzed by a heterogeneous catalyst (eg "Oxy-Catalyst" from Hydrogen Link Inc) and cocatalyzed with a phase transfer catalyst (PTC) that comprises a quaternary ammonium salt, for example, a quaternary ammonium hydrogen sulfate;

c) contacting the primary oxidized hydrocarbon material with an extractant to allow at least a portion of the sulfoxide and / or sulfone compounds to be extracted into the extractant in order to provide a sulfoxide and / or sulfone stream and a low sulfur hydrocarbon stream;

Y

d) contacting the sulfoxide and / or sulfone stream with a tertiary oxidant to provide an aqueous sulfite stream and a low sulfur aromatic hydrocarbon stream,

wherein the tertiary oxidant oxidizes sulfone and / or sulfoxide compounds to sulfite compounds.

[0029] In the above two embodiments, a secondary oxidant is not used in the process, as described hereinbefore in step b). In the process according to this embodiment only the primary and tertiary oxidant are used, as described hereinbefore.

[0030] In a third aspect, a process is provided for reducing the sulfur content of a hydrocarbon material containing sulfur compounds, the process comprising:

a) contacting the hydrocarbon material with one or more primary oxidants to provide an oxidized primary hydrocarbon material such that the primary oxidant oxidizes sulfur compounds to sulfoxide and / or sulfone compounds, wherein the primary oxidant selected from one or more of the group consisting of N-chloroimide, hypobromous acid, electrolyzed oxidizing water, and catalyzed and cocatalyzed hydrogen peroxide;

c) contacting the primary oxidized hydrocarbon material with an extractant to allow at least a portion of the sulfoxide and / or sulfone compounds to be extracted into the extractant to provide a sulfoxide and / or sulfone stream and a stream low sulfur hydrocarbon; Y

d) separating the sulfoxide and / or sulfone stream from the low sulfur hydrocarbon stream.

[0031] In a preferred embodiment of the third aspect, the primary oxidant is catalyzed and cocatalyzed hydrogen peroxide.

[0032] The catalyzed and cocatalyzed hydrogen peroxide can be hydrogen peroxide catalyzed by homogeneous or heterogeneous catalysts, including catalysts selected from the group that includes, but is not limited to, transition metals, noble metals, and rate control catalysts. degradation; and cocatalyzed by a Phase Transfer Catalyst (PTC).

[0033] Degradation rate control catalysts include, but are not limited to, phosphotungstic acid (PTA). Phosphotungstic acid can be formed from sodium tungstate dihydrate (Na2WO4.2H2O) and phosphoric acid.

[0034] PTC can be selected from the group including but not limited to: quaternary ammonium salts including, but not limited to: quaternary ammonium hydrogen sulfates, such as tri-C8-10-alkylmethyl, hydrogen sulfates (for example Ultra C , which is a proprietary PTC available in and developed by Ultraclean Fuel and PTC Organics); methyltrialkyl (C8-C1ü) ammonium chloride (for example Adogen® 464 available from Evonik Industries); and N-methyl-N, N-dioctyloctane-1-ammonium salts such as chloride (eg Aliquat® 336 available from BASF); or equivalent PTC's known to those skilled in the art.

[0035] In an embodiment of the third aspect, the primary oxidant is catalyzed and cocatalyzed hydrogen peroxide wherein the catalyzed and cocatalyzed hydrogen peroxide is phosphotungstic acid catalyzed hydrogen peroxide comprising dihydrated sodium tungstate and phosphoric acid and cocatalyzed with a phase transfer catalyst (PTC) comprising a quaternary ammonium hydrogen sulfate.

In another embodiment of the third aspect, the primary oxidant is catalyzed and cocatalyzed hydrogen peroxide wherein the catalyzed and cocatalyzed hydrogen peroxide is hydrogen peroxide catalyzed by a heterogeneous catalyst, such as "Oxy-catalyst" (Hydrogen Link , Inc) and cocatalyzed by a phase transfer catalyst (PTC).

According to step c) of the third aspect disclosed herein, at least a part of the sulfoxide and / or sulfone compounds are extracted in an extractant to provide a sulfone / sulfoxide stream and a low sulfur hydrocarbon stream apart. The extractant can be a polar extraction solvent selected from the group consisting of acetonitrile, DMF, DMSO, methanol, water, brine, and furfural or an ionic liquid (IL). In one embodiment, the extraction solvent is acetonitrile.

Optionally, the process according to the third aspect further includes a step of contacting the primary oxidized hydrocarbon material with a secondary oxidant to provide a secondary oxidized hydrocarbon material, hereinafter referred to as step b), wherein the secondary oxidant is selected from one or more of the group consisting of hydroxyl radicals, liquid ferrate (iron VI), chlorine dioxide, and hyperfluoro acid / polar liquid solvent, such that the secondary oxidant oxidizes sulfur compounds to sulfoxide and / or sulfone compounds.

[0039] Optionally, the process according to the third aspect further includes a step of contacting the sulfoxide and / or sulfone stream with a tertiary oxidant to supply an aqueous sulfite stream and a low sulfur aromatic hydrocarbon stream, to the hereinafter referred to as step e), wherein the tertiary oxidant oxidizes sulfone and / or sulfoxide compounds to sulfite compounds.

[0040] Optionally, the process according to the third aspect further includes a step of contacting the secondary oxidized hydrocarbon material formed in step b) with an extractant to allow at least a part of the sulfoxide compounds and / or sulfone is extracted into the extractant in order to provide a sulfoxide and / or sulfone stream and a low sulfur hydrocarbon stream.

[0041] In a particular embodiment of the third aspect disclosed herein, a process is provided for reducing the sulfur content of a hydrocarbon material containing sulfur compounds, the process comprising the steps of:

a) contacting the hydrocarbon material with one or more primary oxidants to provide a primary oxidized hydrocarbon material such that the primary oxidant oxidizes sulfur compounds to sulfoxide and / or sulfone compounds, wherein the primary oxidant is peroxide catalyzed and cocatalyzed hydrogen peroxide and wherein the catalyzed and cocatalyzed hydrogen peroxide is hydrogen peroxide catalyzed by phosphotungstic acid and cocatalyzed with a phase transfer catalyst (PTC) comprising a quaternary ammonium salt, for example an ammonium hydrogen sulfate quaternary;

c) contacting the primary oxidized hydrocarbon material with an extractant such as acetonitrile, to allow at least a portion of the sulfoxide and / or sulfone compounds to be extracted into the extractant in order to provide a sulfoxide stream and / or sulfone and a low sulfur hydrocarbon stream;

Y

d) separating the sulfoxide and / or sulfone stream from the low sulfur hydrocarbon stream.

[0042] In another particular embodiment of the third aspect disclosed in this document, a process is provided to reduce the sulfur content of a hydrocarbon material containing sulfur compounds, the process comprising the steps of:

a) contacting the hydrocarbon material with one or more primary oxidants to provide a primary oxidized hydrocarbon material such that the primary oxidant oxidizes sulfur compounds to sulfoxide and / or sulfone compounds, wherein the primary oxidant is peroxide catalyzed and cocatalyzed hydrogen peroxide and wherein the catalyzed and cocatalyzed hydrogen peroxide is hydrogen peroxide catalyzed by a heterogeneous catalyst, such as "Oxy-catalyst" ( Hydrogen Link, Inc), and cocatalyzed with a phase transfer catalyst (PTC ) comprising a quaternary ammonium salt, for example, a quaternary ammonium hydrogen sulfate;

c) contacting the primary oxidized hydrocarbon material with an extractant such as acetonitrile, to allow at least a portion of the sulfoxide and / or sulfone compounds to be extracted into the extractant in order to provide a sulfoxide stream and / or sulfone and a low sulfur hydrocarbon stream;

Y

d) separating the sulfoxide and / or sulfone stream from the low sulfur hydrocarbon stream.

[0043] In the above two embodiments, a specific primary oxidant is used in the process. The additional use of a secondary and / or tertiary oxidant in the process is optional.

[0044] In still another embodiment of the first, second, and third aspects, a process is provided for reducing the sulfur content of a hydrocarbon material containing sulfur compounds, the process comprising the steps of:

a) contacting the hydrocarbon material with one or more primary oxidants to provide a primary oxidized hydrocarbon material such that the primary oxidant oxidizes sulfur compounds to sulfoxide and / or sulfone compounds, wherein the primary oxidant is catalyzed and cocatalyzed hydrogen peroxide and wherein the catalyzed and cocatalyzed hydrogen peroxide is hydrogen peroxide catalyzed by phosphotungstic acid or a heterogeneous catalyst, such as "Oxy-Catalyst" (Hydrogen Link Inc), and cocatalyzed with a transfer catalyst phase (PTC) comprising a quaternary ammonium salt, for example, a quaternary ammonium hydrogen sulfate;

b) contacting the primary oxidized hydrocarbon material with a secondary oxidant to provide a secondary oxidized hydrocarbon material in which the secondary oxidant is selected from one or more of the group consisting of hydroxyl radicals, liquid ferrate (iron VI) , chlorine dioxide and hyperfluorous acid / polar liquid solvent, such that the secondary oxidant oxidizes sulfur compounds to sulfoxide and / or sulfone compounds.

c) contacting the primary oxidized hydrocarbon material and / or the secondary oxidized hydrocarbon material with an extractant, such as acetonitrile, to allow at least a portion of the sulfoxide and / or sulfone compounds to be extracted into the extractant in order to provide a stream of sulfoxide and / or sulfone and a stream of hydrocarbons low in sulfur;

d) separating the sulfoxide and / or sulfone stream from the low sulfur hydrocarbon stream; Y

e) contacting the sulfoxide and / or sulfone stream with a tertiary oxidant to provide an aqueous sulfite stream and a low sulfur aromatic hydrocarbon stream,

wherein the tertiary oxidant oxidizes sulfone and / or sulfoxide compounds to sulfite compounds.

[0045] The primary oxidant oxidizes sulfur compounds in the hydrocarbon material to sulfoxides and / or sulfones to provide a material primary oxidized hydrocarbons. According to the second aspect and a preferred embodiment of the first and third aspects, the primary oxidant is selected from one or more of the group consisting of N-chloroimide, hypobromous acid, electrolyzed oxidant water, and catalyzed / cocatalyzed hydrogen peroxide as described. defined herein above. Generally, the primary oxidant is used to oxidize electron-rich sulfur compounds, as well as sulfides, disulfides, and mercaptans. Preferably, the primary oxidant oxidizes sulfur compounds with an electron density at the sulfur atom greater than about 5.739.

[0046] In one embodiment of the second aspect, the primary oxidizer has an oxidation potential (ORP) of up to about 1.55 (1.550 mV).

[0047] In an embodiment of the first, second, and third aspects, the primary oxidant is N-chloroimide. N-chloroimide can be prepared by the reaction of sodium hypochlorite, water, and an imide, preferably cyanuric acid. Most preferably, the N-chloroimide is prepared in situ, and is prepared as required in the course of the process of the invention.

[0048] In another embodiment, the primary oxidant is hypobromous acid. Hypobromous acid can be prepared by electrolysis of hydrogen bromide in water, more preferably, it is prepared in situ by electrolysis of hydrogen bromide in water. In a preferred embodiment, regeneration of bromine by electrolysis allows recycling of the primary oxidant.

[0049] In another embodiment, the primary oxidant is catalyzed and cocatalyzed hydrogen peroxide. The catalyzed and cocatalyzed hydrogen peroxide is as defined above.

[0050] In one embodiment, the primary oxidant is electrolyzed oxidant water. The electrolyzed oxidizing water can be prepared according to known methods.

[0051] The hydrocarbon material containing sulfur compounds is preferably a liquid hydrocarbon material containing sulfur compounds. Examples of preferred liquid hydrocarbon materials containing sulfur compounds include, but are not limited to, diesel fuels, turbine jet fuel feedstock, natural gas condensate (NGC).

[0052] In one embodiment, the hydrocarbon material is contacted with the primary oxidant in at least a stoichiometric amount for the conversion of sulfur compounds to sulfoxide and / or sulfone compounds and thereby provide the oxidized hydrocarbon. primary. In another embodiment, the amount of primary oxidant is proportionally dosed with a ratio equivalent to between 2 moles and 4 moles of oxidant relative to 1 mole of sulfur, for example, as detected by an online Total Sulfur Analyzer.

[0053] In one embodiment, the hydrocarbon material is brought into contact with the primary oxidant at a temperature in the range of about: 20 ° C-70 ° C, 50-70 ° C, 50-65 ° C, 55 -65 ° C, 60-65 ° C, 30-65 ° C or 20-40 ° C and a pressure in the range of approximately: 20 PSI (140 kPa) -100 PSI (700 kPa), 20 PSI (140kPa) -50 PSI (350kPa), or 30 PSI (210 kPa) -50 PSI (350 kPa).

[0054] In one embodiment, the hydrocarbon material is heated in the range of about 30-65 ° C before step a). Preferably, it is introduced into the primary oxidation reactor at a pressure in the range of about 140 kPa to 350 kPa.

[0055] The primary oxidant may be introduced into the reactor primary oxidation while the hydrocarbon material.

[0056] In some embodiments, the primary oxidant is used in the absence of catalysts (such as transition and / or noble metals) or cocatalyst (such as quaternary ammonium salts such as Phase Transfer Catalyst (PTC)). In other embodiments, such as when hydrogen peroxide is the primary oxidant, catalysts and cocatalysts are present.

[0057] In the first aspect and preferred embodiments of the second and third aspect, the primary material oxidized hydrocarbon is oxidized further using the secondary oxidant to oxidize any further sulfur compounds not oxidized by the first oxidizing.

[0058] The process according to the second aspect allows the hydrocarbon material to be oxidized by the primary oxidant, the secondary oxidant or both primary and secondary oxidants depending on the sulfur species present in the hydrocarbon material. In one embodiment, the primary oxidized hydrocarbon material contains both sulfur-containing compounds and sulfoxide and / or sulfone compounds. In this embodiment, it may be desirable to further contact the primary oxidized hydrocarbon with the secondary oxidant to oxidize the remaining sulfur compounds. This may be necessary if the hydrocarbon being processed contains more thiophenes and benzothiophenes, as these species are resistant to oxidation. Without imposing theoretical limits, this is considered in part due to their relatively low electron densities or to their deficiency or lack of electrons. For example, thiophene in the form of trimethyl benzothiophene has been found to be highly resistant to oxidation.

[0059] Primary and secondary oxidants oxidize sulfur compounds to sulfoxide and / or sulfone compounds to provide an oxidized hydrocarbon material.

[0060] According to the second aspect and a preferred embodiment of the first and third aspects, the secondary oxidant is selected from one or more of the group consisting of hydroxyl radicals, liquid ferrate (iron VI), chlorine dioxide or hiperfluoroso acid / polar solvent.

[0061] According to the second and third aspects, the secondary oxidant can also be used and after treatment with the primary oxidant or instead of the first oxidant. In one embodiment, the primary oxidized hydrocarbon material contains sulfoxide and / or sulfone compounds but no sulfur-containing compounds. In this In this embodiment, no additional oxidation steps are required to oxidize the sulfur compounds. In another embodiment, the secondary oxidant oxidizes any sulfur compounds that have not been oxidized by the primary oxidant to sulfoxide and / or sulfone compounds. Generally, a secondary oxidant will be required if the primary oxidant does not measurably oxidize the sulfur compounds in the hydrocarbon material.

[0062] The secondary oxidant is used primarily to oxidize sulfur compounds that are relatively electron-poor (ie have a low electron density at the sulfur atom). Preferably, the secondary oxidant oxidizes sulfur compounds with an electron density at the sulfur atom of <5.73.

[0063] According to the first aspect and a preferred embodiment of the second and third aspects, the secondary oxidant has an oxidation-reduction potential (ORP) of> 1550 mV. In one embodiment, the secondary oxidant has an oxidation-reduction potential (ORP) of> 1700 mV. In another embodiment, the ORP of the secondary oxidant is> 1900 mV. In another embodiment, the ORP is in the range of about 1550-2200 mV. The secondary oxidant has a higher ORP than the primary oxidant.

[0064] In one embodiment, the secondary oxidant is brought into contact with the material primary oxidized hydrocarbon or hydrocarbon material in at least a stoichiometric amount for converting sulfur compounds into compounds of sulfoxide and / or sulfone and thus it provides the secondary oxidized hydrocarbon material. In another embodiment, the secondary oxidant is contacted with the primary oxidized hydrocarbon material or hydrocarbon material in a stoichiometric excess of> 1 mole of oxidant relative to about 1 mole of sulfur, or of about 1-3 moles of oxidant to about 1 mole of sulfur, or about 2-3 moles of oxidant to about 1 mole of sulfur. The secondary oxidant can be brought into contact with the primary oxidized hydrocarbon material or the hydrocarbon material at a temperature of less than about 35 ° C, or in the range of about 15-35 ° C and at a pressure of less than about 700 kPa, or in the range of about 100-700 kPa; or about 125-350 kPa. In one embodiment, the contact occurs for a period of time in the range of about 30 seconds to 10 minutes, or about 40 seconds to 5 minutes, or about 1-4 minutes.

[0065] In a specific embodiment of the first, second and third aspects, the secondary oxidant is chlorine dioxide which can be in the form of a stabilized water solution having a chlorine dioxide content in the range of about 3000 ppm (0 , 3%) at 8000 ppm (0.8%). Chlorine dioxide can be supplied to the reaction at a temperature in the range of about 15-35 ° C, or about 18-25 ° C and at a pressure of about 140 kPa to 700 kPa.

[0066] In another specific embodiment of the first, second and third aspects, the secondary oxidant is hypofluoro acid in a polar solvent including, but not limited to, acetonitrile. In this embodiment, hypofluorous acid in acetonitrile can be prepared by bubbling a gaseous mixture comprising fluorine and nitrogen in liquid acetonitrile to form the oxidant in the form of an electrophilic oxidant of HOF.CH3CN, in which the concentration of fluorine mixed ( mixed) with Nitrogen does not exceed about 20% by weight, or is in the range of about 15% to 20%, or in the range of about 10% to 15% by weight of fluorine blended with the nitrogen. In one embodiment, the secondary oxidant is supplied to a secondary oxidation reactor at room temperature, or less than about 25 ° C (77 ° F), or about 20 ° C (68 ° F), or about 15 ° C ( 59 ° F) and at a pressure in the range of approximately 30 PSI (140 kPa) to 100 PSI (700 kPa).

[0067] In another embodiment of the first, second, and third aspects, the secondary oxidant is hydroxyl radicals. In this embodiment, a stoichiometric amount of the secondary oxidant can be added to the secondary oxidation reactor in the range of about 1 minute to 5 minutes, or about 2 minutes to 4 minutes, or about 3 to 3.5 minutes, at a lower temperature. at approximately 25 ° C (77 ° F), or at approximately 25-15 ° C, or at approximately 20 ° C (68 ° F), or at approximately 15 ° C (59 ° F) and at a pressure in the range of approximately 30 PSI (140 kPa) to 100 PSI (700 kPa).

[0068] In still another specific embodiment of the first, second and third aspects, the secondary oxidant is Liquid Ferrate VI. In this embodiment, a stoichiometric amount of the secondary oxidant can be added to the secondary oxidation reactor and the Liquid Ferrate is produced in situ by reaction involving caustic soda, bleach, and ferric chloride. Liquid Ferrate VI can be mixed vigorously with the hydrocarbon material or oxidized first hydrocarbon for a time in the range of about 1 - 5 minutes, or about 2 minutes to 4 minutes, or about 3 to 3.5 minutes at a time. temperature below about 25 ° C (77 ° C), or in the range of about 25-15 ° C, or about 20 ° C (68 ° F), or about 15 ° C (59 ° F) and at a pressure in the range from about 30 PSI (140 kPa) to 100 PSI (700 kPa).

[0069] Empirical tests have confirmed that the oxidation of sulfur compounds is not significantly more complete after two oxidation cycles. Accordingly, in a preferred embodiment of the given process As disclosed herein, it will be more efficient if no more than two oxidation cycles are required since the level of effective oxidation decreases very markedly after two oxidation reactions.

[0070] According to step c) of the first, second and third aspects disclosed herein, at least a part of the sulfoxide and / or sulfone compounds are extracted in an extractant to provide a sulfone / sulfoxide and a separate low sulfur hydrocarbon stream. In one embodiment, most or all of the sulfoxide and / or sulfone compounds are extracted into the extractant. The extractant may be in the form of an ionic liquid (IL) or an alternative polar extraction solvent. In one embodiment, the primary and / or secondary oxidized hydrocarbon material is brought into contact with an ionic liquid (IL) or a polar extraction solvent for a time and under conditions to allow at least a portion of the hydrocarbon compounds to sulfoxide and / or sulfone is extracted or absorbed in the extraction solvent or liquid. In one embodiment, the extractant is a polar extraction solvent selected from the group consisting of DMF, DMSO, methanol, water, brine, furfural, acetonitrile. For example, a liquid / liquid extraction or ion exchange adsorption process can be used to extract the sulfone / sulfoxide compounds.

[0071] The extractant can be an IL of the general composition Q + A-, where Q + is a phosphonium or quaternary ammonium cation and A- is an inorganic or organic anion, selected such that the IL is in a liquid state at the operating temperature and pressure of the process.

[0072] Multiple extractions and water washes can be carried out in the process of the first, second and third aspects disclosed herein. In one embodiment, most or all of the sulfoxide and / or sulfone compounds are extracted into an aqueous extractant to provide a low sulfur hydrocarbon stream upon contact with an aqueous extractant. In another embodiment, most or all of the sulfoxide and / or sulfone compounds are extracted into an aqueous extractant to deliver a low sulfur hydrocarbon stream after multiple aqueous extractions, that is, after contact with more than one aqueous extractant. .

[0073] The primary or secondary material can be oxidized hydrocarbons contact the extractant directly or after oxidation or optionally after an extraction step with water washing.

[0074] The step of contacting the hydrocarbon material with the oxidant can be carried out with the extractant, simultaneously with or after contact with the extractant.

[0075] In one embodiment, a part of the sulfoxide and / or sulfone compounds can be extracted from the primary oxidized hydrocarbon material after steps a) and from the secondary oxidized hydrocarbon material after step c), to provide a stream sulfone / sulfoxide and a low sulfur hydrocarbon stream.

[0076] According to an embodiment of the first, second and third aspects, the first and / or second material oxidized hydrocarbons obtained from step a) and / or step c) are washed with water.

[0077] According to another embodiment of the first, second and third aspect, step c) further includes a washing step with water before the current sulfoxide and / or sulfone and current low sulfur hydrocarbons are separated.

[0078] The tertiary oxidant oxidizes the sulfoxide compounds and / or sulfone sulfite compounds in step d) of the first and second aspects and a preferred embodiment of the third aspect of the processes disclosed herein. It will be understood that the tertiary oxidant will have a force that is capable of oxidizing the sulfoxide and / or sulfone group of a compound to a sulfite group. In one embodiment, the tertiary oxidant is a caustic solution. The tertiary oxidant can be selected from the group consisting of:

i) sodium hydroxide,

ii) potassium hydroxide; Y

iii) hydroxyl radicals.

[0079] In other embodiments, the oxidation with the tertiary oxidant is carried out in a range of about 40-95 ° C.

[0080] In one embodiment, sodium hydroxide is the tertiary oxidant. Oxidation of the sulfone and / or sulfoxide compounds with sodium hydroxide solution forms aqueous sodium sulfite. The sodium hydroxide solution can be in a concentration of about 30-60%, or about 50%. Preferably, the stoichiometric ratio of sulfone and / or sulfoxide to sodium hydroxide is about 1: 1. The oxidation can be carried out at a temperature in the range of about 40-95 ° C, or about 50-85 ° C or about 75 ° C. In one embodiment, the tertiary oxidant and the sulfoxide and / or sulfone stream are stirred for a period of up to about 12 minutes, or up to about 10 minutes, or up to about 8 minutes, or about 5 minutes.

[0081] In another embodiment, the tertiary oxidant is hydroxyl radicals. The oxidation of the sulfone and / or sulfoxide compounds with hydroxyl radicals forms a sulfite and after the addition of water forms sulfuric acid. Preferably, the stoichiometric ratio of hydroxyl radicals to sulfone / sulfoxide is in the range of about 1: 1 to 4: 1, in one embodiment the stoichiometric ratio is about 2: 1, in another it is about 1: 1. The oxidation can be carried out at a temperature of up to about 75 ° C, or up to about 70 ° C, or up to about 65 ° C, or in the range of about 20 ° C (68 ° F) to 50 ° C ( 122 ° F) for a period sufficient to oxidize sulfoxide / sulfone compounds (SO / SO2) to sulfite compounds (SO3). In one embodiment, the hydroxyl radicals may be present as UV catalyzed humid air or catalyzed H2O2 components. The tertiary oxidant and the sulfoxide / sulfone rich stream can be stirred for a period in the range of about 10-20 minutes.

In another embodiment, the low sulfur hydrocarbon stream and the low sulfur aromatic compound are combined and recycled as a low sulfur hydrocarbon fuel.

[0083] In one embodiment in accordance with all aspects, the sulfur content of the hydrocarbon material is analyzed prior to contact with the first and / or second oxidant using known detectors such as a Sulfur Sensitive X-ray Fluorescence Detector. In another embodiment, the mass of sulfur is determined. In still another embodiment, the mass and content of sulfur compounds is determined.

[0084] In another embodiment, the sulfite compounds produced by oxidation with the tertiary oxidant are used for further processing.

The process according to the first, second and third aspects may further comprise: e) contacting the low sulfur hydrocarbon stream obtained in step c) with an adsorbent to remove residual sulfur compounds from the stream low sulfur hydrocarbon stream to provide an ultra low sulfur (or ULSD) hydrocarbon stream. In one embodiment, the adsorbent is selected from physical or physicochemical adsorbents, preferably Y zeolite, activated carbon, Cu-impregnated chabazite, Fuller's earth, and metal oxide structures (MOF).

[0086] In another embodiment, after step e) the loaded absorbent is regenerated / purged using N2 stripping by heating to desorb sulfur compounds from the adsorbent.

[0087] In accordance with the invention claimed herein, the process includes the step of separating the sulfone / sulfoxide stream and the low sulfur hydrocarbon stream produced in step c).

[0088] In a preferred embodiment of the first, second and third aspects, the low sulfur hydrocarbon stream is polished to remove any residual sulfur compounds using adsorbents that include MOF (Organic Metal Structures) groups including but not limited to Basolite ( C18H6Cu3O12) - Copper Benzene-1,3,5-tricarboxylate), group of adsorbents of the type Selexsorb Metal Oxide Purification Adsorbent, CuCl2MIL-47 MOF, Zeolite Y, Chitosan Molecular Impression, Chabazite impregnated with Cu, Fuller's Earth or Activated carbon.

[0089] In another embodiment of the process of the first, second and third aspects, after step d), the aromatic compound stream is mixed with the low sulfur hydrocarbon stream.

[0090] The process according to the first, second and third aspects may further include a pre-mixing step before step a).

[0091] In a fourth aspect, there is provided a method for regenerating an aromatic and / or aliphatic sulfone and / or sulfoxide compound into a sulfone and / or sulfoxide-free aromatic and / or aliphatic compound comprising contacting the compound of sulfone and / or aromatic and / or aliphatic sulfoxide with hydroxyl radicals to form the aromatic or aliphatic compound free of sulfone and / or sulfoxide and a sulfite.

[0092] In one embodiment, the sulfite is hydrated to sulfuric acid.

[0093] In another embodiment, the aromatic and / or aliphatic sulfone and / or sulfoxide compound is the sulfoxide / sulfone compound formed in the process according to the first, second, or third aspect disclosed herein.

[0094] In a fifth aspect, there is provided a method for oxidizing a sulfur-containing hydrocarbon material to a sulfoxide and / or sulfone-containing hydrocarbon material, comprising contacting the sulfur-containing hydrocarbon material with an oxidant primary selected from the group consisting of N-chloroimide, hypobromous acid, catalyzed and cocatalyzed hydrogen peroxide and electrolyzed oxidizing water, wherein the hypobromous acid is prepared in situ by electrolysis of hydrogen bromide in water and preferably wherein the acid Hypobromous is regenerated and recycled in the process that follows the oxidation of the sulfur-containing hydrocarbon material.

[0095] In one embodiment of the fifth aspect, hydrogen peroxide is catalyzed by homogeneous or heterogeneous catalysts, including catalysts selected from the group that includes, but is not limited to, transition metals, noble metals, and rate control catalysts. degradation; and cocatalyzed by a Phase Transfer Catalyst (PTC) as disclosed herein in accordance with the first aspect. In one embodiment, the catalyst is PTA as described hereinbefore. In another embodiment, the catalyst is a heterogeneous catalyst, such as "Oxy-catalyst" produced by Hydrogen Link, Inc.

[0096] In a sixth aspect, there is provided a method of oxidizing a sulfur-containing hydrocarbon material to a sulfoxide and / or sulfone-containing hydrocarbon material, comprising contacting the sulfur-containing hydrocarbon material with an oxidant secondary selected from one or more from the group consisting of hydroxyl radicals, liquid ferrate (iron VI), chlorine dioxide and hyperfluoro acid / acetonitrile.

[0097] In one embodiment, hydroxyl radicals are produced in situ by exposing moist air to TiO2 catalyzed by UV light energy.

[0098] In a seventh aspect, the use of quaternary ammonium salts as a cocatalyst with hydrogen peroxide catalyzed in the oxidation of sulfur compounds in a hydrocarbon material is disclosed.

[0099] In one embodiment of the seventh aspect, the catalyzed hydrogen peroxide is hydrogen peroxide catalyzed by homogeneous or heterogeneous catalysts, including catalysts selected from the group that includes, but is not limited to, transition metals, noble metals, and control catalysts. of the rate of degradation.

[0100] Degradation rate control catalysts include, but are not limited to, phosphotungstic acid. Phosphotungstic acid can be formed from sodium tungstate dihydrate (Na2WO4.2H2O) and phosphoric acid.

[0101] In one embodiment, the catalyst is PTA as described hereinbefore. In another embodiment, the catalyst is a heterogeneous catalyst, such as "Oxy-catalyst" produced by Hydrogen Link, Inc.

[0102] In another embodiment of the seventh aspect, the quaternary ammonium salts are PTC selected from the group that includes, but is not limited to: tri-C8-10-alkylmethyl, hydrogen sulfates (eg Ultra C, which is a proprietary PTC available in and developed by Ultraclean Fuel and PTC Organics); methyltrialkyl (Cs-C10) ammonium chloride (eg Adogen 464 available from Evonik Industries); and N-methyl-N, N-dioctyloctane-1 ammonium salts such as chloride (eg Aliquat 336 available from BASF).

[0103] In an eighth aspect, an apparatus is disclosed for desulfurizing a liquid hydrocarbon material containing sulfur compounds according to the process described in the third aspect, the apparatus comprising: a) one or more oxidation reactors for oxidizing the sulfur-containing liquid hydrocarbon material with the primary oxidant (s) to form the primary oxidized hydrocarbon material;

b) one or mixers for mixing the primary oxidized hydrocarbon material with an extraction solvent in order to extract at least a part of the sulfones / sulfoxides in the extractant and provide an extractant containing sulfones / sulfoxides and a hydrocarbon solution low in sulfur;

c) one or more separators, such as one or more coalescers, to separate the sulfone / sulfoxide-containing extractant from the low-sulfur hydrocarbon solution, and

d) one or more adsorbents to polish the low sulfur hydrocarbon solution to provide an ultra low sulfur hydrocarbon solution.

[0104] In one embodiment, the apparatus is as shown in Figure 4-6. In another embodiment, the apparatus is as described in Figure 2. In still another embodiment, the apparatus is as described in Figure 3.

Definitions

[0105] By sulfur compound, it will be understood that the compound contains a group -S-, -S-S-, Metal = S, C = S or -SH.

[0106] By sulfoxide compound, it will be understood that the compound contains a -S (= O) - group.

[0107] By sulfone compound, it will be understood that the compound contains a -S (= O) 2.

[0108] By "hydrocarbon material containing sulfur compounds" will be understood to mean material composed of aliphatic and / or aromatic hydrocarbons containing sulfur compounds that will be subjected to the process disclosed herein to reduce sulfur content. Hereinafter, it may also be referred to as "hydrocarbon feedstock", "feedstock", or "feed stream", and so on.

[0109] It will be understood that "low sulfur hydrocarbon", as referred to in step c) in the first and second aspects and preferred embodiments of the third aspect described herein, means that the proportion of sulfur compounds in the hydrocarbon material is less than the proportion of sulfur compounds in the "hydrocarbon material containing sulfur compounds" as it existed before step a), which is before contact with the primary and / or secondary oxidants. In a preferred embodiment, an "ultra low sulfur hydrocarbon" or "ULSD" stream is produced from the low sulfur hydrocarbon stream. ULSDs will be understood to have a lower sulfur content than "low sulfur hydrocarbon".

[0110] The "low sulfur hydrocarbon stream" may contain sulfoxide and / or sulfone compounds in varying amounts depending on the degree of their removal after aqueous extraction.

[0111] The term "sulfoxide and / or sulfone stream" as referred to in step c) in the first and second aspects and preferred embodiments of the third aspect described herein, will be understood to mean any amount of sulfoxide and / or sulfones obtained after aqueous extraction of the oxidized hydrocarbon material. It will be appreciated that the "stream" obtained from a first extraction of an oxidized hydrocarbon material may contain more sulfoxide and / or sulfone than subsequent vapors obtained after multiple extractions of the same oxidized hydrocarbon material.

[0112] By "low sulfur aromatic hydrocarbon", as referred to in step d) in the first and second aspects and preferred embodiments of the third aspect of the invention, will be understood to mean that the proportion of sulfur compounds in the aromatic hydrocarbon material is less than the proportion of sulfur compounds in the "hydrocarbon material containing sulfur compounds" as it existed before step a), which is before contact with the primary and / or secondary oxidants. Hereinafter, it may also be referred to as "low sulfur aromatic" or, in a preferred embodiment, "ultra-low sulfur aromatic hydrocarbon" or "ULS aromatics" where the sulfur level is below of the "aromatic low in sulfur".

[0113] Aromatics ULS typically refers to a PAH (polynuclear aromatics) level of <5% by volume in Japan, Australia and most of Europe, with the exception of Sweden, which has a maximum limit of <3%. In the United States, particularly California, the total aromatics concentration is 10% by volume, while in most US states the limit is substantially higher.

Brief description of the drawings

[0114]

Figure 1 shows an elementary flow diagram of a preferred embodiment of the process disclosed herein.

Figure 2 shows a general scheme for the process disclosed herein in accordance with a preferred embodiment of the second aspect using a primary oxidant.

Figure 3 shows a general scheme for the process disclosed herein in accordance with a preferred embodiment of the first or second aspect using a primary and secondary oxidant.

Figure 4 shows a general diagram corresponding to the feed preparation step for the process disclosed herein in accordance with a preferred embodiment of the third aspect of the invention.

Figure 5 shows a general scheme corresponding to the oxidation step for the process disclosed herein in accordance with a preferred embodiment of the third aspect of the invention.

Figure 6 shows a general diagram corresponding to the separation and adsorption step for the process disclosed herein in accordance with a preferred embodiment of the third aspect of the invention.

Key to Figures 4-6

[0115]

PIT - Pressure Indicating Transmitter.

FIT - Flow Indicator Transmitter

TIT - Temperature Indicating Transmitter

LIT - Level Indicator Transmitter

DPIT - Differential Pressure Indicating Transmitter

AIT - Analysis Indicator Transmitter (Sulfur Analyzer)

VFD - Variable Frequency Drive

M - Motorized

HS diesel - diesel containing sulfur

PTC - Phase Transfer Catalyst

PTA - Phosphotungstic acid

ACN - Acetonitrile

Detailed description of realizations

[0116] In one embodiment, the process disclosed herein uses an oxidation philosophy combined with an additional process that transforms sulfoxides and / or sulfones into sulfur-free aromatic hydrocarbons that can remain in the hydrocarbon-containing stream. ultra-low sulfur if sulfur-free aromatics can be mixed into the ultra-low-sulfur hydrocarbon stream and do not violate the maximum aromatics specifications, thus allowing the aromatic hydrocarbon to mix with the ultra-low sulfur hydrocarbon stream. However, if the aromatics limits are reached, the separated ultra-low-sulfur aromatics can be marketed as a valuable low-sulfur aromatic hydrocarbon stream.

[0117] This enables the production of ultra-low sulfur hydrocarbons, such as diesel (ULSD) containing aromatic hydrocarbons, or optionally a separate ULSD stream in addition to an ultra-low sulfur aromatics stream. Accordingly, in one embodiment, the process disclosed herein is capable of providing a usable side stream containing, in addition to sulfur-free aromatic hydrocarbons, a separate stream of aqueous salts and / or sulfuric acid, thereby HC (hydrocarbon) components are not lost or the loss is minimal.

[0118] It will be appreciated that if the separated aromatic hydrocarbon is remixed with the Ultra Low Sulfur (ULSD) hydrocarbon stream, no hydrocarbon loss is experienced, although the ULSDs will contain aromatics, some of which may be undesirable. and in fact may require their removal to meet future and even current specifications that dictate the maximum total aromatic and / or maximum polyaromatic content of ULSDs.

[0119] In accordance with one embodiment of the process disclosed herein, the sulfoxide and / or sulfones can be extracted from the oxidized hydrocarbon stream using sulfoxide / sulfone extraction techniques whereby a ULSD stream is produced. low aromatics in addition to a sulfoxide / sulfone stream. Such sulfoxide / sulfone extraction techniques include, but are not limited to, "liquid / liquid" extraction using polar solvents, "distillation" or "adsorption" using ion exchange techniques or a combination of techniques. Such techniques are well known and understood to those skilled in the art.

[0120] The extracted sulfoxide / sulfone stream can be treated to produce only low sulfur aromatic hydrocarbons and aqueous salts or sulfuric acid. This embodiment does not expose the entire oxidized hydrocarbon stream to the sulfone / sulfoxide conversion process, only the extracted sulfone / sulfoxide stream. Low sulfur aromatic stream can be used as high value raw material in petrochemical industry. If specifications permit, this sulfur-free aromatic stream can be remixed into the ULSD stream. The salts can be used as an added value proposition, in much the same way as elemental sulfur produced by the desulfurization of light hydrocarbons using the well known and accepted combination of HDS and Claus processes.

[0121] A synoptic overview of one embodiment of the process disclosed in this document is provided below. The stages that are described are in functional order. Various embodiments of this basic process are described in more detail below. The process according to one embodiment comprises the following cascading steps:

1) First-stage oxidation of hydrocarbon material containing electron-rich sulfur compounds using N-chloroimide, Electrolyzed Oxidizing Water, catalyzed and cocatalyzed hydrogen peroxide (as described hereinbefore) or Hypobromous Acid as primary oxidant or first stage oxidant. 2) Washing with oxidized hydrocarbon water followed by organic / aqueous phase separation and extraction of polar oxidized sulfur compounds using polar liquid extraction solvent in a liquid / liquid extraction or ion exchange adsorption process.

3) Second-stage oxidation using oxidants with a higher oxidation strength, either Hydroxyl Radical, Liquid Ferrate (Iron VI) or Hypofluorous Acid / Acetonitrile as secondary oxidant. According to the second aspect disclosed herein, this second oxidation step may not be necessary and depends on the mass and species of sulfur in the raw material (hydrocarbon material).

4) Washing oxidized hydrocarbon with water followed by organic / aqueous phase separation and extraction of polar oxidized sulfur compounds using polar liquid extraction solvent in a liquid / liquid extraction or ion exchange process.

5) Separate oxidized hydrocarbon material (containing sulfoxides / sulfones) from said polar liquid extraction solvent using vacuum flash distillation or equivalent techniques such as intense centrifugation to achieve said separation. This separation is typically used when solvent extraction is used, although when ion exchange adsorption is used, recovery of extracted compounds and regeneration of media are accomplished by processes known and accepted by those skilled in the art.

6) Tertiary oxidation of sulfur compounds separated from the oxidized hydrocarbon material (containing sulfoxides and / or sulfones) to form two phases as a consequence of said oxidation. Such oxidation can be accomplished by further oxidation of sulfoxides / sulfones to sulfites - using a tertiary oxidant selected from sodium hydroxide or hydroxyl radicals to produce sodium sulfite (Na2SO3), water, and sulfur-free aromatics when using sodium hydroxide as tertiary oxidant. When hydroxyl radicals are used for said tertiary oxidant, the sulfoxide / sulfone is oxidized to sulfite- and hydrated to produce sulfuric acid (H2SO4) and sulfur-free aromatic compounds. The removal of sulfides and otherwise lost (aromatic / aliphatic) hydrocarbon compounds provides a system to allow either the addition of sulfur-free aromatics back to the Ultra Low Sulfur Hydrocarbon stream or optionally the provision of sulfur-free aromatic hydrocarbon compounds for use in industry, which enables added value to the owner of said desulfurized hydrocarbon.

Oxidation and oxidants

Oxidation of sulfur compounds using primary (Stage 1) and secondary (Stage 2) oxidants

[0122] The process disclosed herein for reducing the sulfur content of a hydrocarbon material containing sulfur compounds includes the oxidation of sulfur-containing compounds using one or more active oxidants, which are the first and / or second oxidants.

[0123] Embodiments of the process disclosed herein support a spectrum of feedstream sulfur compounds ranging from disulfides, and mercaptans, to the more demanding organosulfide compounds, such as heterocyclic sulfur-containing compounds that are Thiophene, benzothiophene (BT), dibenzothiophene (DBT), 4-methyldibenzothiophene (MDBT), 4,6-dimethyl-dibenzothiophene (DMDBT), and methyldibenzothiophene. In one embodiment, a diverse range of raw materials can be treated comprising a total sulfur content ranging up to> 20,000 ppm.

[0124] In accordance with the present discussion, the primary oxidant will typically oxidize electron-rich sulfur compounds, as well as sulfides, disulfides, and mercaptans that can typically allow the oxidation of more than 50% of the total sulfur in the fuel stream. feeding. Therefore, considering the mass and species variation of the sulfur-containing compounds in the feedstock will be beneficial in determining whether the use of the primary and / or secondary oxidant is required. This is an important attribute of the process disclosed herein, leading to greater flexibility of the desulfurization ability of the process.

[0125] According to the first aspect, the primary oxidant has an oxidation-reduction potential of up to 1550 mV and the secondary oxidant has an ORP of> 1.55.

[0126] According to the second aspect, the process allows flexibility in oxidation as to which oxidant is used relative to whether a primary and / or secondary oxidant is used.

[0127] In one embodiment of the first and third aspects and in accordance with the second aspects, the primary oxidant includes at least one member selected from the group consisting of:

a) N-chloroimide,

b) hypobromous acid,

c) electrolyzed oxidizing water

e) catalyzed and cocatalyzed hydrogen peroxide

and the secondary oxidant is selected from one or more of the group consisting of:

f) ferrate (Iron VI),

g) hypofluoro acid,

h) chlorine dioxide,

i) hydroxyl radicals.

[0128] In another embodiment of the first and third aspects and the second aspect of the process disclosed herein, the primary oxidant is typically used to oxidize the higher electron density sulfur compounds (electron rich sulfur compounds), such as DMDBT and DBT, which are very susceptible to exchange or give up electrons that are easily absorbed by oxygen that later replaces the sulfur atom of the hydrocarbon molecules. This produces oxidized sulfur molecules in a two-stage reaction; the first reaction is sulfur oxidized to sulfoxide followed by the second reaction; the latter being sulfoxide oxidized to sulfone.

[0129] In certain embodiments, the choice of oxidants will be dictated by factors such as the total sulfur content and the distribution and amounts of the various sulfur compounds in the feed stream and the demographics of the location. The physical location of the plant has a considerable effect on transport costs in the case of oxidants that are not generated on site and have to be transported to a remote location, for example. These factors have an impact on operating expenses.

[0130] If the sulfur content is> 1000 ppm of which there is a high percentage of benzothiophenes, it is unlikely that the primary oxidant alone quantifiably oxidizes such sulfur compounds. However, the processes disclosed herein provide flexibility to treat a wide range of sulfur masses and species.

[0131] The secondary oxidant is used to oxidize residual sulfur compounds that are relatively electron-poor and therefore require a stronger oxidant or have higher electronegativity whereby they are better able to oxidize such recalcitrant sulfur compounds.

[0132] Some feed streams have sulfur components that are more difficult to oxidize, rather than the electron-rich sulfur compounds mentioned above. To oxidize more electron-deficient (low electron density) sulfur compounds that may be present in the hydrocarbon material, stronger oxidants are required, represented by secondary oxidants. The comparative electron density in the sulfur atom is defined as difficult, while the electron density decreases in the following order; DMDBT>DBT> BT.

[0133] If the feed stream contains a large percentage of thiophene compounds, the secondary oxidant, such as the hydroxyl radical or Liquid Ferrate (Iron VI), will be required in addition to or in place of the primary oxidant. Electrolyzed oxidizing water may be a particularly useful option if the sulfur compounds are more sulfides, disulfides, mercaptans, and high electron density organosulfide species.

[0134] The processes disclosed herein also incorporate various other options for the secondary oxidant. The second stage oxidant can also be Liquid Ferrate (iron VI) or stabilized hypofluoro acid.

[0135] Consideration of the logistics of each plant and the various locations, including transportation costs, dictates that if sodium hypochlorite or electrolyzed oxidizing water is used as primary or secondary oxidants, the sodium hypochlorite or electrolyzed oxidizing water is will be generated on-site using electrolysis technology from a brine solution known to those skilled in the art. In a preferred embodiment, the Free Available Chlorine (FAC) concentration ranges from about 1% to 14%. In situ oxidant generation can be advantageous as it allows continuous production of N-chloroimide oxidant, which is the combination of sodium / water hypochlorite and cyanuric acid. This combination produces a relatively efficient oxidation medium capable of oxidizing thiols and most disulfide compounds commonly found in hydrocarbon streams such as middle distillate, fuel oil, and light ends. In still another embodiment, the processes disclosed herein encompass the use of a bromide oxidant, which is hydrobromic acid at a concentration of up to 60%, more typically 48%. The hydrobromic acid in this oxidant is electrolyzed which, as a consequence, converts the bromide ion to bromine which, when reacts with water, produces the active oxidant, hypobromous acid. Catalyzed and cocatalyzed hydrogen peroxide

[0136] As indicated above, the catalyzed and cocatalyzed hydrogen peroxide can be hydrogen peroxide catalyzed by homogeneous or heterogeneous catalysts, including catalysts selected from the group that includes, but is not limited to, transition metals, noble metals, and catalysts degradation rate control (or decomposition catalyst); and cocatalyzed by a Phase Transfer Catalyst (PTC).

[0137] In one embodiment, degradation rate control catalysts (or decomposition catalyst) include, but are not limited to, phosphotungstic acid (PTA). Phosphotungstic acid can be formed from sodium tungstate dihydrate (Na2WO4.2H2O) and phosphoric acid.

[0138] In another embodiment, the catalyst is a heterogeneous catalyst, such as "Oxy-catalyst" produced by Hydrogen Link, Inc.

[0139] Typical PTC's are known to those skilled in the art and can be used as a cocatalyst in the process disclosed herein. PTC may be selected from the group including, but not limited to: quaternary ammonium salts including, but not limited to, quaternary ammonium hydrogen sulfates, such as tri-C8-10-alkylmethyl, hydrogen sulfates (for example Ultra C, n. CAS 355009-64-2) and methyltrialkyl (Ce-Ci0) ammonium chloride (for example Adogen® 464 available from Evonik Industries) and salts of N-methyl-N, N dioctyloctane-1-ammonium, such as chloride (eg Aliquat® 336 available from BASF); or equivalent PTC's known to those skilled in the art.

[0140] Ultra C (C8Hi7-CioH2i) 3NCH3 + HSO4 ", (CAS # 355009-64-2) can be prepared by modifying a chlorine-based Adogen® compound (eg 464) and substituting the Cl with HSO4. This can be achieved according to known techniques. The inventors have found that this modified PTC provides a marked increase in the efficiency of PTC in the sulfur oxidation reaction compared to the use of chlorine-based PTC's, such as Adogen® and Aliquat®.

[0141] In a preferred embodiment, the primary oxidant is catalyzed and cocatalyzed hydrogen peroxide wherein the catalyzed and cocatalyzed hydrogen peroxide is phosphotungstic acid catalyzed hydrogen peroxide and cocatalyzed with a phase transfer catalyst (PTC) comprising a Quaternary Ammonium Hydrogen Sulfate.

[0142] The present inventors have discovered that when hydrogen peroxide is used as the primary oxidant, then a catalyst and a cocatalyst are required to ensure the quantitative oxidation of all sulfur compounds. In one embodiment, PTC is used as the cocatalyst when the process disclosed herein uses catalyzed hydrogen peroxide as the oxidant. In another embodiment, phosphotungstic acid (PTA) is the catalyst. In another embodiment, a heterogeneous catalyst, such as "Oxy-catalyst" produced by Hydrogen Link, Inc. is the catalyst.

[0143] In connection with the preparation of PTA for use in the process disclosed herein, the present inventors have also discovered that changing the ratio of dehydrated sodium tungstate to phosphoric acid affects oxidation of sulfur-containing compounds. Specifically, small increases in phosphoric acid have been shown to aid qualitative oxidation of sulfur. Without imposing theoretical limits, the inventors believe that this is due to the extra protons which is helpful in the process of electron exchange (oxidation).

[0144] The inventors have discovered that without a cocatalyst, such as PTC, the amount of hydrogen peroxide must be drastically increased to the point that its use is not feasible. The inventors have found that even using about 10-20 times the stoichiometric amount of hydrogen peroxide and repeating the oxidation cycle up to 5 times did not quantitatively oxidize sulfur compounds.

[0145] Without imposing theoretical limits, the inventors believe that without the oxygen transfer attributes achieved by a PTC of quaternary ammonium hydrogen sulfate, eg Ultra C, the reaction is not as efficient as oxygen migration between the organic and aqueous phase is kinetically limited without using a PTC, which results in excessive use of hydrogen peroxide and an excessively long reaction time. Quaternary ammonium hydrogen sulfate PTC, for example Ultra C, provides efficient oxygen mass transfer at the interface of the aqueous and organic layer.

N-chloroimide

[0146] N-chloroimide can be produced by reacting sodium hypochlorite mixed with water and stabilized with an imide, such as cyanuric acid, succinimide, acetamide and piperidine. In one embodiment, the imide used is cyanuric acid. Sodium hypochlorite can be in a concentration range of about 3% to 17.5% by weight, or about 3% to 12% by weight, or about 5% to 10% by weight. .

[0147] The preparation of this oxidant is based on the premise that sodium hypochlorite reacts with imides such as cyanuric acid, succinimides and acetamide, to produce N-chloroimide. Said oxidant uses cyanuric acid as the imide in this discussion, although any imide is suitable for N-chloroimide. The following oxidizing action is proposed in this exhibit:

- Sodium hypochlorite reacts with the selected imide in the aqueous phase to produce N-chloromide, which is transferred to the organic phase.

- N-chloroimide oxidizes sulfur compounds to produce sulfoxides and sulfones.

[0148] N-chloroimide is prepared using the following recipe:

Sodium hypochlorite at a concentration of 12.5% = 0.1553 moles

Cyanuric Acid = 0.0052 moles.

[0149] The above oxidant was used to oxidize sulfur in a 3.8 liter (1 gallon) sample of diesel fuel containing 500 ppm sulfur. It is also noted that the components in the recipe may differ from those listed above and still produce a functional oxidant, and therefore the discussion using this recipe is not limited to the recipe listed.

Hypobromous acid

[0150] According to the present disclosure, hypobromous acid can be generated by either of two methods: i) Electrolysis of hydrobromic acid thus producing bromine to which water is added to produce hypobromous acid; or ii) reacting hydrobromic acid with water and sodium hypochlorite.

i) Electrolysis of hydrobromic acid

[0151] Hypobromous acid production can be achieved by electrolysis of hydrogen bromide in water. Hydrogen bromide electrolysis is known to result in the transformation of bromide ions to bromine, which, in the presence of water, produces hypobromous acid. This technique is the preferred method of producing said hypobromous acid according to the process disclosed herein. This production method provides the ability to minimize the consumption of hydrobromic acid, as the bromide ion that is produced as a result of sulfur oxidation is continuously electrolyzed using standard electrolysis equipment, thus forming bromine. Such a manufacturing technique using electrolysis is well known to those skilled in the art.

[0152] In a preferred embodiment, electrolyzed hydrobromic acid is prepared by passing hydrobromic acid at a concentration of 48% through a bromination cell, whereby the electrolysis action transforms the bromide ions into Bromine. Such cells are widely available and are known to those skilled in the art. The bromine produced at the anode of said cell is reacted with water to the point of saturation. The oxidant produced is hypobromous acid. As a result of the oxidation of sulfur compounds, the hypobromous acid is reduced to bromide ions which are subsequently electrolyzed when the cycle is restarted to produce hypobromous acid. This process is described in this case as the in situ production of hypobromous acid.

[0153] Accordingly, in one embodiment, hypobromous acid is prepared in situ by electrolysis of hydrogen bromide in water, wherein regeneration of bromine by electrolysis allows recycling of the primary oxidant. In this embodiment, bromine is regenerated after oxidation of the sulfur-containing hydrocarbon compound and reduction of the hypobromous acid to bromide ions which are then available for further electrolysis to form bromine and for recycling in the process.

ii) Hydrobromic acid with water and sodium hypochlorite

[0154] This alternative strategy used to generate hypobromous acid is less preferred since the chemical components in the oxidant are sacrificed. The main chemical component is sodium hypochlorite in the range of approximately 5% to 12.5% concentration mixed in a solution of hydrobromic acid at approximately 48% concentration and water and mixed to achieve a pale yellow solution and a pH of 7 which indicates that almost 95% - 100% of the solution is hypobromous acid. This methodology remains an optional technique in the process disclosed herein for producing hypobromous acid, although the lack of ability to regenerate the oxidant (sodium hypochlorite) presents a penalty on operating costs. In this methodology, the oxidation of the bromide ion is carried out using sodium hypochlorite instead of using electrolysis to achieve the production of hypobromous acid.

[0155] In the preparation of hypobromous acid the following recipe and procedure can be used according to an embodiment of the invention:

- Hydrobromic acid at a concentration of 48% = 52.37 grams Water = 7.132 mls

- Sodium hypochlorite at a concentration of 12.5% = 246.16 grams.

[0156] The hypobromous solution recipe can be used to oxidize sulfur in a 3.8 liter (1 gallon) sample of diesel fuel containing 500 ppm sulfur. It is prepared by adding said amount of water to a beaker containing said amount of hydrobromic acid while continuously stirring for up to 2 minutes. Said amount of sodium hypochlorite is added to this solution, although this amount may vary depending on the color and pH of the resulting solution. The optimum color is pale yellow and an optimum pH is between 6.8 and 7. After the preparation of this oxidizing solution, it should be used within 5 minutes or less, preferably within 3 minutes of its preparation. It should also be noted that the components in the recipe may differ from those listed above and still produce a functional oxidant, and therefore the discussion using this recipe is not limited to the recipe listed.

Hydroxyl radicals

[0157] Hydroxyl radicals are chosen as a secondary oxidant because of their higher oxidation force that is required to oxidize electron-poor sulfur compounds.

[0158] Hydroxyl radicals can be generated by passing humidified, preferably saturated, air through a UV support that catalyzes titanium dioxide or a similar catalyst. Such generators are available today and are known to those skilled in the art of advanced oxidation techniques.

[0159] In one embodiment, hydroxyl radicals are produced by the action of moist air photolysis; said photolysis is preferably achieved by radiation of humid air with UV light with an emission spectrum between 185 and 254 at 385 nm together with titanium dioxide (TO2 / UV).

[0160] According to one embodiment, hydroxyl radicals are in situ using a hydroxyl generator.

[0161] In preferred embodiments, the generation of said hydroxyl radicals is carried out locally and as close as possible to the entry point of the oxidation reactor. To mitigate the risk of hydroxyl radical cleavage before entering the oxidation reactor, the alternative option is to generate such hydroxyl radicals within the reactor. In one embodiment, the hydroxyl radicals can be generated by methods known to those skilled in the art of advanced oxidation process techniques. This can be achieved by using visible light with a wavelength of approximately 400 nm to 700 nm and adding visible light catalyst to the hydrocarbon in such a way that the light energy activates said catalyst thereby producing said hydroxyl radicals as oxidant. Visible light catalysts may be necessary because the photon energy supplied by UV light is absorbed by any aromatics in the liquid hydrocarbon. This occurs in the spectrum of UV light at wavelengths up to 380nm, and the remaining portion of UV light up to 400nm will provide insufficient and inefficient activation energy for use in such an application.

[0162] In one embodiment, the generation method is through UV / TO2 catalytic conversion of moisture-containing air (humid air). It is preferred that the relative humidity is in the range of about 30% to 90%, more preferably about 40% to 80%, most preferably about 55% to 70%.

[0163] In one embodiment, hydroxyl radicals are generated in situ by reacting moist air with UV light catalyzed titanium dioxide (TO2) with a wavelength in the range of about 185 nm - 385 nm, or 254-385 nm. , and in a hydroxyl radical generator, said technique being known by those versed in the art of advanced oxidation processes. The amount of hydroxyl radical used is preferably based on between 2.1 and 3 moles of hydroxyl radicals to oxidize 1 mole of sulfur. It is observed that this stoichiometry varies empirically and, although it is not desired to impose theoretical limits, it is assumed that the stoichiometry will vary according to the amount of oxidizable compounds and the pH of the raw material.

[0164] As noted above, hydroxyl generation can also be achieved by other techniques recognized by those skilled in the art of advanced oxidation processes (AOP), such as catalyzing hydrogen peroxide with Fe ++ compounds or radiation UV ozone or by reacting hydrogen peroxide with ozone, such as those methods listed below:

O3 / H2O2 / UV

O3 / UV

H2O2 / UV

H2O2 / O3

[0165] In a preferred embodiment, the hydroxyls are produced using a proprietary UV chamber in which Ti / O2 coated air baffles were exposed to said UV light through which ambient air was passed with approximately 70% humidity at a rate of 56.6 l / min (2 SCFM). The flow calculation was based on the moisture conversion in the air being approximately 70%, thus producing enough radicals to oxidize approximately 500 ppm of sulfur in the hydrocarbons in the feed stream. A stoichiometric ratio of about 2 moles of oxidant to about 1 mole of sulfur was used as the basis for the amount of hydroxyl to be used to oxidize sulfur with a feed rate of about 3.8 liters / minute (1 gallon / minute ).

Electrolyzed oxidizing water

[0166] In a preferred embodiment, the electrolyzed oxidizing water is prepared elsewhere and supplied by two manufacturers, using electrolytic techniques known to those skilled in the art. The electrolyzed oxidizing water samples used in oxidation tests ranged from ORP 700 to 1200 and pH from 2.5 to 6.5. Tests were carried out using a 1: 1 volume ratio of liquid hydrocarbon to electrolyzed oxidizing water in 5.7 liters (1.5 gallons) of liquid hydrocarbon. The reaction at room temperature was allowed to proceed for 15 minutes.

Stabilized hypofluoro acid

[0167] The secondary oxidant can be hypofluoro acid stabilized in a polar solvent such as acetonitrile. Acetonitrile stabilized hypofluoro acid is the strongest electronegative compound in which a combination of fluorine and nitrogen is mixed. Preferably, the concentration of fluorine mixed with nitrogen does not exceed 20% by weight, preferably 15% to 20%, more preferably 10% to 15% by weight, the balance being nitrogen. In one embodiment, the ratio of fluorine to nitrogen can vary between a mixture of 10% fluorine in 90% nitrogen and 20% fluorine and 80% nitrogen. This gaseous mixture is added to acetonitrile which stabilizes the oxidant. More specifically, the oxidant is prepared by bubbling the reduced fluorine concentration gas mixture comprising fluorine and nitrogen in liquid acetonitrile to form HOF.CH3CN electrophilic oxidant.

[0168] Hypofluoro acid mixed and stabilized in acetonitrile is described in the writings of its pioneer Shlomo Rozen. Rozen et al discovered that this hypofluoro acid stabilized in a solution of Acetonitrile, thus producing a stable solution of HOF.CH3CN, has an optimal capacity to oxidize numerous compounds where Acetonitrile acted as an oxygen transfer agent. The oxidizing power of this solution is not dissolved fluorine and it is not the source of electrophilic fluorine, but is actually the source of an electrophilic oxygen atom. Therefore, the oxidant is known to be a complex between the very unstable and therefore not very useful hypofluoro acid HOF and aqueous acetonitrile. The complex comprises HOF mixed with 1 molar equivalent of acetonitrile. The acetonitrile solvent complex produced by the oxidant mentioned above contains water with a minimum acetonitrile content of 10%.

[0169] In accordance with the present disclosure, hypofluorous acid is preferably prepared according to the following recipe: for 3.8 liters (1 gallon) of diesel containing 500 ppm of sulfur, the following recipe 20% Fluorine in Nitrogen = 0.000228 moles (0.00865 grams) 90% acetonitrile and 10% water = 1 molar equivalent of HOF.

[0170] Fluorine / nitrogen mixtures are readily available from commercial suppliers, such as Air Products and Linde, although the preferred methodology for the production of hypofluoro acid is the use of on-site fluorine generators such as those manufactured and supplied by companies such as Linde.

Liquid Ferrate (Iron VI)

[0171] The secondary oxidant ferrate liquid (Iron VI) can be used alone or together with chlorine dioxide, preferably in the gaseous phase and at a concentration of up to 10% in air or nitrogen. In a preferred embodiment, liquid ferrate (iron VI) is generated in situ using a proprietary process. The liquid ferrate generator is used in the same way as other liquid oxidants and with the same reaction conditions and changed stoichiometric conditions; that is, the oxidation stoichiometry varies to accommodate the oxidative capacity of Fe IV of 2200 mV where ferrate is reacted in an oxidation reactor with a ratio of approximately 0.67 moles of ferrate per 1 mole of sulfur for a time of less than about 5 minutes at a temperature up to about 25 ° C at a pH in the range of about 7 to 8. The pressure conditions do not vary from those of optional secondary oxidants.

Chlorine dioxide gas

[0172] The secondary oxidant can be chlorine dioxide preferably as dilute gas at a concentration <10% in air or nitrogen. In one embodiment, the gaseous chlorine dioxide is produced in situ using chlorine dioxide generators known to those skilled in the art. Chlorine dioxide is considered a relatively strong oxidant due to its 5 available electrons that form the basis for oxidation caused by electron transfer and subsequent oxygen substitution on sulfur molecules. In one embodiment, the chlorine dioxide stoichiometry used is as follows:

For the oxidation of a 3.8 liter (1 gallon) diesel sample containing 500 ppm sulfur; Chlorine dioxide = 0.0129 mol.

Detailed description of a specific embodiment

[0173] In one embodiment of the process disclosed herein for reducing the sulfur content of a liquid hydrocarbon material containing sulfur compounds, the process comprises:

• At least one oxidation step initially, optionally followed by a second oxidation step comprising rapid mixing of the hydrocarbon material with a primary and optionally secondary oxidant as previously described herein, in at least an amount stoichiometric for a time and under conditions sufficient to convert sulfur compounds to a sulfoxide and / or a sulfone and thereby produce oxidized sulfur-containing hydrocarbon;

• at least one extraction step preferably using a flux through a magnetic filter with a magnetic field of at least 11,000 Gauss, after said oxidation steps. Such magnetic filtration attracts polar sulfoxides / sulfones, thereby extracting substantially polar compounds from the hydrocarbon stream. An additional polishing step after said magnetic filtration comprising contacting any remaining oxidized sulfur containing hydrocarbon with an Ionic Liquid (IL) or aqueous polar extraction solvent such as acetonitrile or Y-butyrolactone (GBL) or making come into contact with said oxidized sulfur compounds through adsorption columns loaded with ion exchange media, MOF (Metallic Organic Structures) such as Basolite® (Ci8H6Cu3Oi2-Copper Benzene-1,3,5-Tricarboxylate), group of adsorbents of the Selexsorb® Metal Oxide Purification Adsorbent type, CuCi2MIL-47 MOF, zeolite, molecular imprint chitosan, Fuller's Earth, Elko or activated carbon. Such contact is required for a time and under conditions sufficient to allow at least any remaining portion of the oxidized sulfur to be extracted into the IL or aqueous extraction solvent or adsorbed with ion exchange material or adsorption media as described. Such contact with either extraction solvent or adsorption will extract remaining polar compounds to provide charged IL or charged aqueous extraction solvent or ion exchange / adsorption columns, and reduced sulfur content hydrocarbons;

• separating the IL or aqueous extraction solvent loaded with Y-butyrolactone, acetonitrile or adsorbed ion exchange media from the reduced sulfur hydrocarbon to provide reduced sulfur hydrocarbon.

It is possible that when IL is used as the optional polar liquid extraction solvent and the charged IL is separated from the reduced sulfur hydrocarbon, traces of IL may remain in the reduced sulfur hydrocarbon which may be undesirable in some cases. This only refers to the use of IL as a polar extraction solvent, although typical extraction and polishing of polar compounds can be ion exchange / adsorption media, whereas liquid extraction solvent options in the present discussion include acetonitrile or Y -butyrolactone.

[0174] Accordingly, a preferred embodiment of the process disclosed herein may further comprise:

• at least one water wash / polish step comprising contacting the reduced sulfur hydrocarbon with water for a time and under conditions sufficient to allow any remaining extraction solution in the reduced sulfur hydrocarbon be absorbed by water; and • separating the water from the hydrocarbon to provide a reduced sulfur content hydrocarbon.

[0175] The hydrocarbon material can be a liquid hydrocarbon material. Examples of liquid hydrocarbon materials include gas oil, fuel oil, jet turbine fuel feedstock, natural gas condensate, kerosene, naphthalene, vacuum gas oil, and fuel oil.

[0176] The amount of oxidant can be placed in an almost stoichiometric amount for the conversion of sulfur compounds into sulfoxides and / or sulfones, the theoretical amount being 2 moles of oxidant per mole of sulfur. In one embodiment, about two to four molar equivalents of oxidant are added per molar equivalent of sulfur. A larger excess of oxidant is typically unnecessary and economically undesirable. In this embodiment, the process comprises two oxidation steps. The first oxidation step is used to oxidize electron-rich sulfur compounds, while the second oxidation step is necessary to oxidize electron-lacking sulfur compounds.

[0177] After said first oxidation step, washing with water and extraction of sulfoxide / sulphone according to the following description follows. The substantially sulfur-free hydrocarbon stream that has undergone the first stage oxidation, the water washing which is not required if hydroxyl radicals are used for said oxidation process, and the extraction, is then exposed to the oxidation stage of second stage, to a wash with water and to extraction. After each oxidation / water wash and extraction step, the aqueous and organic phases are separated using coalescence, OSN membrane (organic solvent nanofiltration) or similar phase separation techniques known to those skilled in the art.

[0178] The process disclosed herein may also optionally comprise a premix step prior to the first oxidation step, in which the hydrocarbon material and oxidant are fed to a static mixer prior to rapid mixing in stirred column, cavitation or film shear type reactors.

[0179] Rapid mixing of the hydrocarbon material and the oxidant can be carried out by contacting both the organic and aqueous / gaseous phases in a Stirred Column, Cavitation or Film Shear reactor, with a residence time of up to 15 minutes. Rapid mixing is achieved with up to five rotor stages within the column. The principles of operation and design of this type of mixer / reactor are well known to those skilled in the art. This mixing causes the oxidant to react due to the exchange of electrons. Electron-rich sulfur compounds exchange electrons with the oxidant causing a substitution of oxygen in the sulfur, thereby oxidizing the sulfur molecule.

[0180] Although not subject to theoretical limitations, the apparent initial oxidation reaction in the oxidation reaction of stage one is very rapid and stage one occurs when atomic oxygen binds to sulfur compounds due to liberation of an electron from sulfur compounds to the first stage oxidant. Without imposing theoretical limits, the inventors believe that the level of oxidation, more specifically electron transfer, depends on the relative electronic state of the sulfur compounds and the relative strength of the oxidant.

[0181] Rapid mixing of hydrocarbon and oxidant liquid phases is provided by PI (Process Intensification) reactors such as Film Shear Reactors, Membrane Contactor, Ultrasonic or Cavitation or by Countercurrent / Cocurrent Stirring Column or Reactors equivalent to temperatures in the range of approximately 20 ° C (68 ° F) to 70 ° C (158 ° F) and a pressure in the range of approximately 140 kPa (20 PSI) to 350 kPa (50 PSI), which can be achieved in reactors of the aforementioned type, resulting in the oxidation of sulfur compounds in the hydrocarbon material occurring in the absence of an oxidation transfer facilitator (PTC - Phase Transfer Catalyst) or a required catalyst when they are used some prior art oxidants. Catalysts are required to control the rate of decomposition of the oxidant, allowing sufficient time to achieve contact and oxidation. Although the mass contact between the oxidant and the organic phase is necessary none of the oxidants used in the oxidation of the first stage, it requires additional catalysts, with the exception of the combination of hydrogen peroxide / phosphotungstic acid / Phase Transfer Catalyst. . This rule also applies to the second stage oxidation process using the second stage oxidants included in this invention.

[0182] It will be appreciated that the pressure, temperature and reactor shaft velocity sufficient to oxidize the sulfur in the compounds will vary with the sulfur compounds present in the hydrocarbon feedstock. Refractory electron-poor sulfur compounds that may be present in the raw material include, but are not limited to, thiophenes, benzothiophenes, alkylated benzothiophenes, dibenzothiophene, and sterically hindered alkylated dibenzothiophenes. Rapid mixing in the reactor at temperatures on the order of about 20 ° C (68 ° F) -70 ° C (158 ° F) and a pressure in the range of 140 kPa (20 pS i) - 350 kPa (50 PSI) it is generally adequate. A VFD (Variable Frequency Drive) controlled reactor shaft speed of between 300 and 2400 RPM is also adequate at these temperatures and pressures.

[0183] The process disclosed herein includes one or more extractions with an Ionic Liquid (IL) or an alternative extraction solvent. The extraction solvent can be brine or water and is preferably water. The pH level of the extraction water can vary between 6.5 and 7.5. The oxidized sulfur-containing hydrocarbon can be contacted with an IL or other polar extraction solvents, such as acetonitrile or previously identified extraction solvents, either directly after oxidation or optionally after an extraction step with Water. The hydrocarbon can be subjected to multiple extractions with IL or acetonitrile and multiple washes with water.

[0184] The step of contacting the hydrocarbon material with the primary and / or secondary oxidant can be performed prior to contacting the extraction solvent. However, if the raw material hydrocarbon has a high olefin content, the extraction solvent can be brought into contact with the raw material hydrocarbon, prior to the oxidation step. This is primarily to reduce the amount of oxidant, which is required due to the diene content, as these components tend to capture the oxidant before the sulfur is oxidized. This is not normally a problem when dealing with diesel, either straight run or cracked, but in some Transmix hydrocarbons this could be a possibility.

[0185] When the hydrocarbon material comprises naphtha or a gasoline fraction or other fractions containing dienes, the step of contacting the hydrocarbon material with the oxidant can be performed after an initial extraction of the naphtha or other fractions of hydrocarbon with an ionic liquid or other polar extraction solvent such as acetonitrile to selectively remove dienes that may otherwise deactivate or hinder the oxidation step.

[0186] The extraction solvent can be an IL of the general composition Q + A ', where Q + is a phosphonium or quaternary ammonium cation and A' is an inorganic or organic anion, selected so that the IL is in a liquid state at the operating temperature and pressure of the process. More specifically, the ionic liquid may have a Q + cation selected from an alkyl pyridinium cation, an alkyl pyrrolidinium cation, an alkyl piperridinium cation, a di alkyl imidazolium cation, a tri-alkyl imidazolium cation, a trialkyl piperazinium cation, a tetra- alkylphosphonium, a tetraalkylarsonium, a tetraalkylanthimonium, and a tetraalkyl ammonium cation, and an A 'anion selected from the group consisting of a halide anion, nitrate anion, alkyl sulfate anions, alkylsulfonate anions, alkyl substituted aryl sulfonates such as the p-toluene anion sulfonate or the perfluorinated derivatives of these anions, an alkylphosphonate anion, an alkylphosphonate anion, an alkylphosphinate anion or the perfluorinated alkyl derivatives of these phosphorus-based anions, carboxylate anions or the perfluorinated carboxylate anions, a thiocyanate anion, a hexafluorophonate anion, an anionos hexafluorofato tetrafluoroborate, dicyanamide anion, a bis (trifluoromethanesulfonyl) imide anion, a halo anion genoaluminate, an organohalogenoaluminate anion, and mixtures thereof.

[0187] Preferably, the IL is selected so that it has a miscibility gap when in contact with the hydrocarbon phase sufficient to minimize unwanted losses of hydrocarbons from the hydrocarbon phase to the ionic liquid phase and losses of the IL extraction solvent to the hydrocarbon phase. It is also preferable that the selected ionic liquid has a miscibility space when in contact with the hydrocarbon phase to minimize stabilization times for phase separation and dispersion of the ionic liquid in the hydrocarbon phase. Furthermore, it is preferable that the IL is selected in a way that allows maximum solubility of oxidized and unoxidized sulfur compounds and other hydrocarbon phase contaminants, such as oxidized and reduced organonitrogen compounds.

[0188] Alternative polar solvents such as acetonitrile, Dimethyl Fumarate (DMF), Dimethyl Sulfoxide (DMSO), furfural or methanol can be used and they are suitably polar. The main drawback of the latter group of polar extraction solvents is that, with the exception of acetonitrile, they are more difficult to regenerate. The other drawback of strong polar extraction solvents is that aromatics of which said sulfur is a part are removed as a complete molecule. As an example, the sulfur in dibenzothiophene is oxidized, and therefore polarized by the results of oxidation that converts said sulfur to dibenzothiophene sulfoxide and / or dibenzothiophene sulfone. The extraction process removes the dibenzothiophene sulfone completely. The process disclosed herein overrides this problem by incorporating an additional processing step that separates the aromatic hydrocarbon from the oxidized sulfur, thereby producing a substantially low sulfur aromatic hydrocarbon stream and an aqueous sodium sulfite or sulfuric acid stream, depending on the choice of the tertiary oxidant. If hydroxyl radicals are the oxidant used, the separated sulfone (SO2) will oxidize to SO3 and hydrate to form sulfuric acid, although if a caustic soda (NaOH) solution is used, sodium sulfite will be produced.

[0189] Sulfoxide / sulfone extraction from oxidized hydrocarbon can be performed at temperatures ranging from 30 ° C (86 ° F) to 100 ° C (212 ° F) and pressures ranging from atmospheric to 50 psi (350 kPa) . For the removal of more complex sulfur compounds, higher temperatures and pressures may be beneficial. The extraction into water can, for example, be carried out up to the boiling point of water at a given pressure. One skilled in the art will appreciate that for a volatile hydrocarbon, such as a natural gas condensate, an increase in pressure at elevated temperatures will be required to maintain the NGC in the liquid phase.

[0190] The ratio of hydrocarbon to extraction solvent can be about 10: 1 or higher, or about 8: 1, or about 5: 1. Smaller relationships are also viable; however, with smaller ratios, the cost of the extraction solvent for the process will be proportionally higher.

[0191] The process disclosed herein is suitable for reducing the sulfur content of a range of hydrocarbon materials, including natural gas condensates, light oils, gas oil hydrocarbons, kerosene and naphtha, reconstituted hydrocarbons to from residual oils, jet fuel for turbines, fuel oil and products of gasification and liquefaction of coal. The process has been found to be highly efficient when used on hydrocarbons from actual oil refinery streams. Such hydrocarbons contain a variety of sulfur compounds of varying complexity and oxidation resistance, depending on the source. Sulfur compounds identified and successfully treated in the NGC and diesel streams are identified in sulfur speciation papers shown later in this discussion. This is in notable contrast to laboratory model hydrocarbon compositions which may include only limited selected sulfur compounds and where the selected and limited hydrocarbon composition has an impact on the efficiency of the process.

[0192] Extraction solvents that can be used in embodiments of the process disclosed herein, whether IL or other designated polar solvents, can be separated and regenerated from S compounds in a simple manner by distillation techniques. , or by means of OSN membrane technologies thus avoiding high volume waste streams and also allowing economical operation.

[0193] The process disclosed herein may include an additional extraction step that is used to polish any minor sulfur that has not been oxidized and quantitatively extracted. In one embodiment, an adsorption step is incorporated in which sulfur molecules are physically or physically / chemically adsorbed on the adsorbent surface. Such techniques are known to those skilled in the art of adsorption. A variety of adsorbents are applied in this discussion, including GAC (Granular Activated Carbon) zeolite, Cu impregnated chabazite, Fuller's earth, molecular imprinting chitosan and molecular sieves, such as BASF's range of Selexsorbs® or their equivalents and the very efficient variety of MOF's (Metal Oxide Structures) such as the Basolite® range of MOF's from BASF or their equivalents. In a preferred embodiment, MOF-type adsorbents are preferred due to their superior adsorbance capacity which is about 6 to 8 times greater than zeolite or activated carbon.

[0194] The liquid hydrocarbon containing substantially reduced sulfur and which has been treated using the oxidation and extraction process mentioned above is passed through said adsorbent column, whereby one column is actively adsorbing while the other column is subjected a breakdown of species of adsorbed sulfur. Said disaggregation is achieved using nitrogen under vacuum and with heating to between 100 ° C (212 ° F) and 200 ° C (392 ° F). Such disaggregation and regeneration techniques are well known to those skilled in the art.

[0195] It is recognized that, in the oxidation process, the sulfur molecule undergoes oxidation of the sulfur atom and, as a result, produces sulfoxides and / or sulfones. It is then recognized that the polar adsorption or extraction steps remove the entire molecule of oxidized sulfur, thus removing small amounts of hydrocarbons (HC). This potential HC is relative to the amount of sulfur in the hydrocarbon feed to be desulfurized. For example, dibenzothiophene (C12H8S) is oxidized to dibenzothiophene sulfoxide (C12H8SO) and dibenzothiophene sulfone (C12H8SO2) where this entire molecule is extracted or adsorbed from the liquid hydrocarbon stream. It is desirable to further recover the HC component of said sulfone molecule to avoid excessive hydrocarbon losses, which is more particularly relevant when the feed streams to be desulfurized have increasing amounts of sulfur in said streams.

[0196] In one embodiment of the process disclosed herein, an additional processing step may be incorporated to recover the HC component from the sulfoxide and / or sulfone. For example, for such a dibenzothiophene (C12H8S), the C12H8 can be recovered as a low sulfur aromatic component and, depending on the total aromatic level as specified, said component can either be re-mixed with the ultra-low sulfur stream or It may well be available as a valuable low sulfur aromatic.

[0197] An important feature of the process disclosed herein is the additional step by which said sulfoxides and / or sulfones are further oxidized either by sodium hydroxide or by hydroxyl radicals. The sulfoxide / sulfone stream recovered through the extraction and / or adsorption processes can be reacted with sodium hydroxide solution at a concentration of about 45% to 55%, or about 49% to 52%. The inventors have found that at a volumetric ratio of sulfone to sodium hydroxide of about 1: 1 and at a temperature in the range of about 45 ° C (113 ° F) to 75 ° C (167 ° F), plus or minus 50 ° C (122 ° F) to 65 ° C (149 ° F), or about 55 ° C (131 ° F) to 60 ° C (140 ° F), with stirring action for a period (residence time ) of about 12 minutes, or about 10 minutes, or up to about 8 minutes, occurs to almost quantitative sulfur removal as aqueous sodium sulfite.

[0198] As an alternative method of recovery of sulfoxides / sulfones, hydroxyl radicals can be used. Hydroxyl radicals, as used in the aforementioned second stage oxidant, can be reacted with said sulfoxides / sulfones in a molar ratio of 1 to 4 moles of hydroxyl radical to 1 mole of sulfone. The preferred stoichiometry is 2 moles of hydroxyl radicals relative to 1 mole of sulfoxide / sulfone. If the sulfoxide is oxidized, the higher stoichiometry will be applied. Said reaction is carried out in a reactor as described in the oxidation reaction, but the reaction is slow unless optional catalysts are used. Said reaction can last for about 10 to 20 minutes at a temperature of up to about 75 ° C, or about 70 ° C, or about 65 ° C. The addition of water produces sulfuric acid, where the component (S0 / SO2) of the sulfoxides / sulfones is oxidized to SO3, thus forming sulfuric acid after hydration.

[0199] Therefore, in at least one embodiment, the process of the present invention for reducing levels of S in liquid HC (hydrocarbons) can be conducted in a simple and economically viable manner with very low and simple waste streams. to manage.

Detailed description of a specific embodiment according to the third aspect

[0200] A process for desulfurizing a Transmix / Diesel feed (fractionated transmix feed diesel) according to the third aspect may use a processing facility comprising i) a feed preparation stage, ii) a feed preparation stage, oxidation and iii) a separation and adsorption step. Such a facility can process 1,500 B / day (63,000 gallons / day). Although there is no practical processing limit, the highest capacity is anticipated to be up to 15,000 B / day (630,000 gallons / day). An example of this type of three-stage processing facility is shown in Figures 4-6.

[0201] In an embodiment according to the third aspect disclosed herein, a process is provided for desulfurizing a Transmix / Diesel feedstock, the process comprising three main process steps:

1) Oxidation of raw material sulfur compounds using hydrogen peroxide in conjunction with phosphotungstic acid and UltraC Phase Transfer Catalyst as described hereinbefore (Ultra C is a proprietary Ultraclean Fuel transfer catalyst). The oxidized gas oil and aqueous phases are separated by a coalescer (gas oil / water coalescer) and the oxidized gas oil phase is then subjected to the next sulfone extraction step as described in step 2 below. Figure 5 outlines a preferred embodiment for this oxidation step.

2) Extraction of "sulfones" using liquid / liquid extraction, where the polar extractant is acetonitrile. The acetonitrile / sulfone solution is separated from the hydrocarbon after this extraction through a coalescer (primary diesel / ACN coalescer). After this separation, the substantially sulfur-free hydrocarbon is then subjected to a final "polishing" as described in step 3 below. The separated charged acetonitrile (sulfone-loaded acetonitrile) is then centrifuged (ACN / sulfone centrifuge) where the sulfones are removed from the acetonitrile which is subsequently recycled. The sulfones are gravity fed to a storage tank for disposal. Figure 6 depicts a separation unit and outlines a preferred embodiment for this step. Although in this particular embodiment the sulfones are not subjected to a tertiary oxidation step, said step is optional.

3) After the "sulfones" are removed, the substantially sulfur-free gas oil is then subjected to the "polishing" step, in which any remaining sulfones or water are removed using an "Adsorbent" in a column. In this embodiment, the adsorbent is "Attapulgite" or the adsorbent generally referred to as Fuller's Earth. Any of the adsorbents described hereinabove can be used, but in the commercial sense, Fuller's Earth (Attapulgite) has been found to be more economically preferred while being readily available in Georgia, USA. Figure 6 depicts an adsorption unit and outlines a preferred embodiment for this step.

[0202] In this embodiment, the raw material has a low sulfur mass and does not warrant the additional step of using a tertiary oxidation step to convert sulfones to low sulfur aromatics and sulfite solution. The low mass of sulfur is due to the low sulfur concentration in the feed and the relatively low diesel yield of this unit. However, it is envisaged that in subsequent higher yield units or units supplied with a higher concentration of sulfur compounds, the tertiary oxidation step will be used.

Modes for carrying out the invention

[0203] The process disclosed herein will now be further described by embodiments that are intended to be illustrative only and not restrictive.

Figure 2

[0204] Figure 2 shows a general schematic for one embodiment of the process disclosed herein. In this embodiment, the initial sulfur content of a hydrocarbon feedstock is measured (Sulfur Analyzer A), item 1 in Figure 2. The hydrocarbon feedstock is heated, if necessary and before delivery to limits. process battery, at a temperature in the range of approximately 30 ° C (86 ° F) to 65 ° C (149 ° F) and is introduced at a pressure in the range of approximately 140 kPa (20 PSI) to 350 kPa ( 50 PSI) in element 2 of primary oxidation reactor. The primary oxidant can be any of the oxidants:

N-chloroimide

Hypobromous acid

Electrolyzed oxidizing water

Catalyzed and cocatalyzed hydrogen peroxide or

as described hereinbefore.

[0205] Any of the primary oxidants (step 1 oxidant) as described above is introduced at the same time as the liquid hydrocarbon material and at a temperature in the range of about 20 ° C (68 ° F) to 30 ° C (86 ° F). The amount of oxidant introduced is proportioned proportionally at a rate equivalent to approximately 2 moles to 4 moles of oxidant with respect to 1 mole of sulfur, as detected by item 1 of Total Sulfur Analyzer (A) online in Figure 2 This oxidant is sufficient to oxidize the sulfur compounds of the hydrocarbon feedstock to sulfoxides and / or sulfones. Said oxidant can be introduced in a stirred column, or in a Film Shear Reactor of the Membrane Contactor Device or in an equivalent reactor 2 in Figure 2. The residence time of the reactor is designed to be in the range of approximately 100 seconds to 380 seconds, in some cases from about 80 seconds to 320 seconds, and in other cases preferably from about 60 seconds to 300 seconds.

[0206] After mixing the hydrocarbon and the oxidant, the resulting oxidation reaction occurs in said reactor 2, and the hydrocarbon / sulfone solution is introduced into a separator element 3 as shown in Figure 2. This separator that can being of the coalescent or centrifugal or electrostatic type, it separates the water that has been released from said reactor. Water is the aqueous component of oxidants as described above, although when hydroxyl radicals are used as oxidant, this aqueous component is the residual moisture contained in the air and is up to 85% of the moisture, which is not converted into hydroxyls in the aforementioned in situ hydroxy generator. If any other primary oxidant mentioned above is used, the water contained in each of Those oxidants are separated in the same manner, but it will be appreciated that the amount of water coalesced from the oxidized hydrocarbon will vary according to the stoichiometric ratios and the water content of the oxidant.

[0207] Sulfones are created by the oxidation of sulfur compounds, this is essentially achieved by the action of atomic oxygen bonding to sulfur to form the sulfone. This process is embodied in a dynamic two-step reaction, which has been described above.

[0208] The sulfone loaded hydrocarbon is then introduced at a temperature in the range of about 30 ° C (86 ° F) to 65 ° C (149 ° F) and at a pressure in the range of 140 kPa (20 PSI) at 350kPa (50 PSI) in a stirred column, or in a Film Shear Reactor of the Membrane Contactor Device or in an equivalent reactor 4 of Figure 2, where water is introduced at temperatures in the range of approximately 30 ° C (86 ° F) to 65 ° C (149 ° F) to buff off any residual oxidant. By volume, the amount of water can vary from approximately 50% to 100% of the volume of hydrocarbon. The residence time of the reactor is designed to range from about 5 seconds to 90 seconds, in some cases from about 10 seconds to 30 seconds, and in other cases from about 5 seconds to 20 seconds.

[0209] The hydrocarbon washed with water is then introduced into the separator 5 of Figure 2. This separator, which can be of the coalescent or centrifugal or electrostatic type, separates the water from the liquid hydrocarbon that comes out of the reactor 4 that can contain very small amounts of muriatic / citric acid, of the hydrocarbon loaded with sulfone.

[0210] The substantially water-free sulfone-loaded hydrocarbon exiting separator 5 in Figure 2 is then introduced into reactor 6 of Figure 2, where the polar extraction solvent is also introduced. The sulfone loaded hydrocarbon is introduced at a temperature in the range of about 30 ° C (86 ° F) to 65 ° C (149 ° F) and at a pressure in the range of about 140 kPa (20 PSI) to 350 kPa (50 PSI), where the polar extraction solvent is introduced at temperatures in the range of about 30 ° C (86 ° F) to 65 ° C (149 ° F) to extract or absorb oxidized sulfur compounds or sulfones. The extraction solvent by volume can vary from 20% to 75% of the hydrocarbon volume. For economic reasons, this amount will be kept at a minimum that is expected to be around 30% to 35%. The residence time of the reactor is designed to range from about 25 seconds to 90 seconds, in some cases from about 20 seconds to 30 seconds, and in other cases from about 15 seconds to 20 seconds.

[0211] After the sulfone extraction process performed in reactor 6, the sulfone stream that is embedded in the polar extraction solvent, is separated from the substantially sulfur-free hydrocarbon through separator 7 in Figure 2. This separator it can be, for example, of the coalescing or centrifugal or electrostatic type.

[0212] After separation of the sulfone-rich extraction stream from the substantially sulfur-free hydrocarbon, the sulfone-rich stream can be distilled in the distillation unit 14 of Figure 2. Distillation techniques can be used, nanofiltration, membrane contactor or RO to recover the extraction solvent and provide a concentrated stream of sulfone. Distillation and separation techniques are well known to those skilled in the art, and distillation characteristics will be determined by the boiling point of the selected extraction solvent.

[0213] The substantially sulfur-free hydrocarbon stream exiting separator 7 in Figure 2 is then introduced into reactor 8 of Figure 2. The hydrocarbon from which the sulfone was removed is introduced at a temperature in the range of approximately 30 ° C (86 ° F) to 65 ° C (149 ° F) and at a pressure in the range of approximately 140 kPa (20 PSI) to 350 kPa (50 PSI), where any residual polar extraction solvent is removed from the hydrocarbon . Water is introduced into reactor 8 of Figure 2 at temperatures in the range of about 30 ° C (86 ° F) to 65 ° C (149 ° F) and at a pressure in the range of about 140 kPa (20 PSI) at 350kPa (50 PSI) to polish any extraction solvent left in the hydrocarbon stream from which the sulfone exiting separator was removed 7. The wash / polish water by volume can vary by an amount of 20% to 75% of the volume of hydrocarbon. The residence time of the reactor is designed to range from about 25 seconds to 90 seconds, in some cases from about 20 seconds to 30 seconds, and in other cases from about 15 seconds to 20 seconds.

[0214] After the hydrocarbon polishing and water washing process performed in reactor 8 in Figure 2, the hydrocarbon phase is introduced into separator 9 of Figure 2, where the ultra-low sulfur hydrocarbon is separated from the polishing water to exit separator 9 in Figure 2 as treated, sulfur-free hydrocarbon. The polishing water separates and becomes used water. The sulfur-free hydrocarbon exiting separator 9 in Figure 2 is then subjected to a polishing step, which removes any sulfones that may have remained in the water-washed hydrocarbon exiting reactor 8 in Figure 2.

[0215] The polishing stage consists of two adsorbent loaded column elements 10 and 11 in Figure 2. One column is in "adsorption" mode while the other is in "desorption" mode. In adsorption mode, the Sulfur-free hydrocarbon is directed to the column currently designated as adsorption mode, which is loaded with media consisting of any of the following adsorbents;

Zeolite Y

Activated carbon

MOF (Metallic Organic Structures) adsorbents such as, but not limited to, CuChMIL-47 (Material from the Lavoisier Institute) or the BASF product line of Basolite® C300 (C18H6Cu3O-i2), Cu-impregnated Chabazite or Fuller's Earth.

[0216] The adsorbent material acts as a physicochemical extraction system in which any remaining sulfur compound, whether oxidized or not, is adsorbed onto the structure of the adsorbent medium. The preferred adsorption cycle is 24 hours, after which the adsorbent must undergo desorption by injecting N2 at a temperature sufficient to vaporize and disaggregate the adsorbed sulfur compounds under vacuum. The temperature is above the boiling point of any retained sulfur compound. This can exceed approximately 250 ° C (482 ° F) at atmospheric pressure, but under vacuum it will be a substantially lower temperature as will be appreciated by those skilled in the art. The hydrocarbon is redirected to the other identical column which is currently in adsorption mode while the previous adsorption mode column switches to desorption mode. The desorption cycle is designed to be exposed to the separation or disaggregation mode with N2 for up to about 4 hours, more preferably about 3 hours, most preferably about 2 hours after which said column is placed in standby mode while waiting to cyclic change back to adsorption mode. During the adsorption cycle in both columns 10 and 11, the hydrocarbon stream that leaves said columns is a sulfur-free hydrocarbon and if said hydrocarbon is a gas oil fraction, the resulting output stream will be ULSD (ultra-low gas oil content). sulfur).

[0217] If the hydrocarbon that comes out of either column 10 or column 11 has not met the sulfur reduction target as measured by item 15 of Total Sulfur Analyzer in line A of Figure 2, installed At the output of the treated hydrocarbon process, the "out of specification" hydrocarbon stream will automatically be diverted to the primary oxidation reactor 2 in Figure 2, for reprocessing.

[0218] The purged or disaggregated sulfur species and the N2 leaving either column 10 or column 11, depending on which column is in desorption mode, is cooled to a nominal temperature of approximately 50 ° C (122 ° F) through conventional heat exchange in the heat exchanger element 12 of Figure 2. This cooled stream exiting the heat exchanger element 12 is directed to a coalescer element 13 or degassing membrane of Figure 2, where the separated N2 is expelled or recycled and sulfur compounds (typically sulfoxides and / or sulfones) are directed to tertiary oxidation.

[0219] The tertiary oxidation is carried out in the reactor element 16 of Figure 2. Said reactor is identical to the oxidation reactors mentioned above. The sulfoxide / sulfone stream that is the combination of disaggregated sulfur compounds from the adsorption columns 10 and 11 in Figure 2 and the residue resulting from the distillation or separation of the sulfone extraction solvent in the distillation unit 14 in the Figure 2 is introduced into reactor 16 of Figure 2. It is introduced at temperatures in the range of approximately 30 ° C (86 ° F) to 65 ° C (149 ° F) and at a pressure in the range of approximately 140 kPa (20 PSI) and 350kPa (50 PSI). A caustic soda solution is also introduced into reactor 9 at a concentration of approximately 5% to 70%. This is introduced at temperatures in the range of about 40 ° C (104 ° F) to 80 ° C (176 ° F) and at a pressure in the range of about 140 kPa (20 PSI) to 350 kPa (50 PSI). This process step is very important and is used to separate the sulfur-free aromatic hydrocarbon component of the sulfone from the sulfone component. The sulfone component is converted to sodium sulfite solution (Na2SO3 H2O) according to the following chemistry:

R-SO2 2NaOH ^ Na2SO3 R H2O

[0220] The sulfur-free aromatic hydrocarbons designated as "R" in the aforementioned chemistry resulting from the reaction in reactor 16 are introduced into separator 17 of Figure 2 where the aromatic hydrocarbon components are separated from the sulfite solution of sodium. This separator is preferably of the coalescing or centrifugal or electrostatic type or an equivalent membrane separation device.

[0221] The Ultra Low Sulfur Aromatics (ULS) stream exiting separator 17 in Figure 2 is introduced into reactor 18 of Figure 2 at temperatures in the range of about 40 ° C (104 ° F) at 80 ° C (176 ° F) and at a pressure in the range of approximately 140 kPa (20 PSI) to 350 kPa (50 PSI). Water is preferably introduced simultaneously into reactor 18 at a temperature in the range of about 40 ° C (104 ° F) to 80 ° C (176 ° F) and at a pressure in the range of about 140 kPa (20 PSI). at 350kPa (50 PSI). The residence time in this reactor is in the range of about 20 seconds to 60 seconds, preferably about 15 seconds to 30 seconds. This step is added to wash the aromatics stream with water, thereby polishing any residual caustic from the aromatics stream.

[0222] The water-washed aromatics stream exiting reactor 18 is then introduced into separator 19 in Figure 2, where the residual caustic soda solution is removed, thus producing ultra-low sulfur aromatics and a raffinate of low concentration sodium sulfite. The water-washed aromatics stream is a potentially valuable by-product with uses in multiple industrial applications, known to those skilled in the art. Most importantly, there is a very low loss of valuable aromatic hydrocarbons and the sulfur is not in the form of highly available elemental sulfur, but in a sodium sulfite solution, which could be dehydrated if necessary.

[0223] If particular locations do not present onerous limitations on Total Aromatics or PAHs or both, the sulfur-free aromatics can be mixed again in the Ultra Low Sulfur Content Hydrocarbon stream leaving columns 10 and / or 11 of adsorption of Figure 2.

Oxidation using catalyzed and cocatalyzed hydrogen peroxide

[0224] In one embodiment according to the first and second aspects of the process described herein, only a primary oxidant is used. In a preferred embodiment, the primary oxidant is a catalyzed and cocatalyzed hydrogen peroxide, preferably hydrogen peroxide catalyzed by phosphotungstic acid resulting from a mixture of sodium tungstate dihydrate and phosphoric acid and cocatalyzed by a PTC, preferably Ultra C.

[0225] Oxidative desulfurization is carried out under conditions slightly above atmospheric (approximately 60-65 ° C) using a mixture of hydrogen peroxide, tungstate to regulate the decomposition of hydrogen peroxide and phosphoric acid in order to protonate the gas oil (so that it is slightly acidic) and PTC with a view to efficiency in oxidation due to the transfer of oxygen from the aqueous phase to the organic phase. After oxidation, the gas oil is sent to a 2-phase separator as illustrated in Item 3 of Figure 2, where the gas oil phase is coalesced from the second phase consisting of water, tungstate / phosphoric acid ( PTA) and PTC. The water and tungstate are then separated from the PTC through a centrifuge, thus regenerating the PTC. The water and tungstate are made to have a reduced water / tungstate ratio by evaporating excess water (introduced by degradation of hydrogen peroxide) and the tungstate-water mixture at the desired concentration is recirculated to the feed tank to its reuse.

[0226] After oxidation and the first separation, the gas oil is subjected to a polar extractant, which is then separated from the gas oil. The extractant is then centrifuged to remove sulfones, thus regenerating the polar extractant. The diesel is then sent to a polishing stage for the removal of high molecular weight contaminants as a final processing step.

Figure 3

[0227] The present invention will now be further described by way of preferred embodiments as described below and with reference to Figure 3, and which are intended to be illustrative only and not restrictive.

[0228] This embodiment adds to the oxidation portion of the process and allows greater flexibility to process more demanding low electron density sulfur hydrocarbon streams or high sulfur mass hydrocarbon streams. These embodiments provide diversity in oxidation cycles by using a different oxidant in the secondary oxidation cycle. This rules out a single point of oxidant failure by using any of the secondary oxidants mentioned above, these options being:

1) Hydroxyl radicals as described above.

2) Chlorine dioxide solution as described above.

3) Hypofluoro acid stabilized in acetonitrile as described above.

4) Liquid Ferrate VI as described above.

[0229] Figure 3 shows a general schematic for another embodiment of the process disclosed in this document. In this embodiment, the initial sulfur content of a hydrocarbon feedstock is measured (Sulfur Analyzer A), item 1 of Figure 3. The hydrocarbon feedstock is heated, if necessary and prior to delivery to limits. process battery, at a temperature in the range of approximately 30 ° C (86 ° F) to 65 ° C (149 ° F) and is introduced at a pressure in the range of approximately 140 kPa (20 PSI) to 350 kPa ( 50 PSI) in element 2 of the primary oxidation reactor of Figure 3. Any of the primary oxidants mentioned above, which are:

N-chloroimide

Hypobromous acid

Electrolyzed oxidizing water

Catalyzed and cocatalyzed hydrogen peroxide or

is introduced at the same time and at a temperature preferably in the range of about 20 ° C (68 ° F) to 30 ° C (86 ° F), when N-chloroimide, electrolyzed oxidizing water, or hypobromous acid is the selected step 1 oxidant . The amount of oxidant introduced is metered proportionally with a ratio equivalent to 2 moles to 4 moles of oxidant with respect to 1 mole of sulfur, as detected by item 1 of the online total sulfur analyzer (A) of Figure 3. This oxidant is sufficient to oxidize the sulfur compounds of the hydrocarbon feedstock to sulfoxides and / or sulfones. If N-chloroimide is used, the constituent sodium hypochlorite is preferably manufactured in situ using brine electrolysis techniques, a concept known and accepted by those skilled in the art. If the process location is such that bulk sodium hypochlorite is available at a concentration of approximately 6% to 24%, this may allow the use of sodium hypochlorite manufactured elsewhere. Said oxidant is introduced into a stirred column or equivalent reactor 2 of Figure 3, at a controlled pH in the range of approximately 4 to 6.5. This pH is controlled by adding either muriatic acid or citric acid at a concentration of 10% to the sodium hypochlorite solution and if the pH falls beyond a desired set point, the control system will add more hypochlorite. sodium until the pH is normalized to the desired set point. The residence time of the reactor is designed to be in the range of about 5 seconds to 90 seconds, or about 10 seconds to 30 seconds, or about 5 seconds to 20 seconds. The same general approach is used when using any of the primary oxidants mentioned above, as long as the oxidant is introduced at the specific stoichiometric ratio and mixed for the appropriate time to allow the sulfur species to oxidize. Different sulfur species respond to oxidants, where in general the primary oxidant preferentially oxidizes electron-rich sulfur compounds, while electron-poor sulfur species require an oxidant having a higher electronegativity, such as those described above. used in the secondary oxidation stage.

[0230] After mixing the hydrocarbon and the oxidant, the resulting oxidation reaction occurs in said reactor 2 in Figure 3, and the hydrocarbon / sulfone / water solution is introduced into a separator 3 in Figure 3. This separator , which can be of the coalescing or centrifugal or electrostatic type, separates all the water from the sulfone-laden hydrocarbon. Sulfones are created by the oxidation of sulfur compounds, this being accomplished essentially by the action of atomic oxygen bonding to sulfur to form the sulfone. This process is embodied in a dynamic two-step reaction, which has been described above.

[0231] The sulfone loaded hydrocarbon is then introduced at a temperature in the range of about 30 ° C (86 ° F) to 65 ° C (149 ° F) and at a pressure in the range of about 140 kPa (20 PSI ) at 350kPa (50 PSI) in a second reactor 4 of Figure 3, where any of the secondary oxidants mentioned above are introduced, which are:

hydroxyl radicals as described above,

chlorine dioxide in solution as described above,

hypofluoro acid stabilized in acetonitrile as described above,

liquid ferrate VI as described above.

The secondary oxidant is used to oxidize remaining unoxidized sulfur compounds, typically the electron-poor species. If the selected secondary oxidant is stabilized chlorine dioxide solution at a concentration in the range of approximately 3000 ppm (0.3%) to 8000 ppm (0.8%), this is introduced at a temperature in the range of approximately 20 ° C (68 ° F) to 35 ° C (95 ° F) and at a pressure in the range of about 140 kPa (20 PSl) to 350kPa (50 PSI) to oxidize sulfur compounds that were not oxidized by the primary oxidant of first stage in reactor 1 of Figure 3. The amount of any selected secondary oxidant will typically be set at a ratio of about 1 mole to 2 moles of oxidant to 1 mole of sulfur. The residence time of the reactor is designed to be approximately 5 seconds to 90 seconds, in some cases 10 seconds to 30 seconds, and in other cases 5 seconds to 20 seconds.

[0232] The secondary oxidized hydrocarbon is then introduced into the separator 5 in Figure 3. This separator, which can be of the coalescing or centrifugal or electrostatic type, separates all the water from the sulfone loaded hydrocarbon. This sulfone-laden hydrocarbon can be subjected to washing with water and, as this step is optional, it is not shown in Figure 3. In addition to this step which is not shown in Figure 3, a choice of oxidation steps can be adopted additional secondary. This plurality of additional oxidation treatments may be desirable, when not necessary, depending on the amount and sulfur compounds present in the raw material hydrocarbon.

[0233] The substantially water-free sulfone-loaded hydrocarbon exiting separator 5 of Figure 3 is then introduced into reactor 6 of Figure 3, where the polar extraction solvent is also introduced. The sulfone loaded hydrocarbon is introduced at a temperature in the range of about 30 ° C (86 ° F) to 65 ° C (149 ° F) and at a pressure in the range of about 140 kPa (20 PSI) to 350 kPa (50 PSI), where the polar extraction solvent is introduced at temperatures in the range of about 30 ° C (86 ° F) to 65 ° C (149 ° F) to extract or absorb the polar oxidized sulfur compounds or sulfones. Extraction solvent by volume can vary from approximately 20% to 75% of the hydrocarbon volume. For economic reasons, this amount will be kept to a minimum and is expected to be in the range of approximately 30% to 35%. The residence time of the reactor is designed to be in the range of about 25 seconds to 90 seconds, in some cases 20 seconds to 30 seconds, and in other cases 15 seconds to 20 seconds.

[0234] After the sulfone extraction process performed in reactor 6 of Figure 3, the sulfone stream that is solubilized in the polar extraction solvent, is separated from the substantially sulfur-free hydrocarbon through separator 7 in Figure 3. This separator can be of coalescing or centrifugal or electrostatic type.

[0235] Following separation of the sulfone-rich stream from the substantially sulfur-free hydrocarbon, the sulfone-rich stream is distilled in distillation unit 14 in Figure 3. Distillation, nanofiltration, or RO techniques can be used to recover the extraction solvent and provide a concentrated sulfone stream. Distillation and separation techniques are well known to those skilled in the art, and distillation characteristics will be determined by the boiling point of the selected extraction solvent.

[0236] The substantially sulfur-free hydrocarbon stream exiting separator 7 in Figure 3 is then introduced into reactor 8 in Figure 3. The hydrocarbon from which the sulfone was removed is introduced at a temperature in the range of approximately 30 ° C (86 ° F) to 65 ° C (149 ° F) and at a pressure in the range of approximately 140 kPa (20 PSI) to 350 kPa (50 PSI), where any residual polar extraction solvent is removed from the hydrocarbon . Water is introduced into reactor 8 in Figure 3 at temperatures in the range of about 30 ° C (86 ° F) to 65 ° C (149 ° F) and at a pressure in the range of about 140 kPa (20 PSI) at 350kPa (50 PSI) to polish any extraction solvent left in the hydrocarbon stream from which the was extracted and exiting separator 7 in Figure 3. The wash / polish water in volume can vary in the range of approximately 20% to 75% of the hydrocarbon volume. The residence time of the reactor is designed to be in the range of about 25 seconds to 90 seconds, in some cases 20 seconds to 30 seconds, and in other cases 15 seconds to 20 seconds.

[0237] After the hydrocarbon polishing and water washing process performed in reactor 8 in Figure 3, the hydrocarbon phase is introduced into separator 9 of Figure 3, where the ultra-low sulfur hydrocarbon is separated from the polishing water to exit the separator 9 of Figure 3 in the form of treated and sulfur-free hydrocarbon. The polishing water separates and becomes used water.

[0238] The sulfur-free hydrocarbon exiting separator 9 in Figure 3 is then subjected to a polishing step, which removes any sulfones that may have remained in the water-washed hydrocarbon exiting reactor 8 in Figure 3 .

[0239] The polishing stage consists of two adsorbent loaded column elements 10 and 11 in Figure 3. One column is in "adsorption" mode while the other is in "desorption" mode. In adsorption mode, the sulfur-free hydrocarbon is directed to the column designated at that time as adsorption mode, which is loaded with media consisting of any of the following adsorbents known to those skilled in the art;

- Zeolite Y

- Activated carbon

- MOF (Metallic Organic Structures) adsorbents such as, but not limited to, CuCl2MIL-47 (Material from the Lavoisier Institute) or the BASF product line of Basolite® C300 (C18H6Cu3012), Cu-impregnated Chabazite or Fuller's Earth.

[0240] The adsorbent material acts as a physiochemical extraction system in which any remaining sulfur compound, whether oxidized or not, is adsorbed onto the structure of the adsorbent medium. The preferred adsorption cycle is 24 hours, after which the adsorbent must be desorbed by injection of N2 at a temperature sufficient to vaporize and disaggregate the adsorbed sulfur compounds under vacuum. The temperature is above the boiling point of any retained sulfur compound. This can exceed 250 ° C (482 ° F) at atmospheric pressure, but in vacuum it will be a substantially lower temperature, as those skilled in the art will appreciate. The hydrocarbon is redirected to the other identical column which is currently in adsorption mode while the previous adsorption mode column switches to desorption mode. The desorption cycle is designed to be exposed to the desorption or disaggregation mode with N2 for up to 4 hours, more preferably 3 hours, most preferably 2 hours after which said column is placed in standby mode awaiting the cyclical change back. to adsorption mode. During the adsorption cycle in both columns 10 and 11, the hydrocarbon stream that leaves said columns is a sulfur-free hydrocarbon and if said hydrocarbon is a gas oil fraction, the resulting output stream will be ULSD (ultra-low gas oil content). sulfur).

[0241] If the hydrocarbon has not met the sulfur reduction target as measured by item 14 of Total Sulfur Analyzer on line A of Figure 3, installed at the outlet of the treated hydrocarbons process, the "Out of specification" hydrocarbon stream will automatically be diverted to the primary oxidation reactor 2 in Figure 3, for reprocessing.

[0242] Purged or disaggregated sulfur species and N2 leaving column 10 or column 11, depending on which column is in desorption mode, is cooled to a nominal temperature of 50 ° C (122 ° F) by conventional heat exchange in the heat exchanger element 12 of Figure 3. This cooled stream exiting the heat exchanger element 12 is directed to a degassing or coalescer membrane element 13 of Figure 3, where the separated N2 it is expelled or recycled and sulfur compounds (typically sulfoxides and / or sulfones) are directed to tertiary oxidation.

[0243] The sulfone stream which is the residue resulting from the distillation or separation of the solvent for the extraction of the sulfones in the distillation unit 14 in Figure 3, is introduced into the reactor 16 of Figure 3. It is introduced at temperatures in the range of about 30 ° C (86 ° F) to 65 ° C (149 ° F) and at a pressure in the range of about 140 kPa (20 PSI) to 350 kPa (50 PSI). A caustic soda solution at a concentration of 5% to 70% is also introduced into reactor 16. This is introduced at temperatures in the range of about 40 ° C (104 ° F) to 80 ° C (176 ° F) and at a pressure in the range of about 140 kPa (20 PSI) to 350 kPa (50 PSI). This process step is very important and is used to separate the sulfur-free aromatic hydrocarbon component of the sulfone from the sulfone component. The sulfone component is converted to sodium sulfite solution according to the following chemistry:

R-SO2 2NaOH ^ Na2SOa R H2O

[0244] The sulfur-free aromatic hydrocarbons resulting from the reaction in reactor 16 in Figure 3 are introduced into separator 17 of Figure 3 where the aromatic hydrocarbon components are separated from the sodium sulfite solution. This separator can be of the coalescing or centrifugal or electrostatic type.

[0245] The sulfur-free aromatic hydrocarbon stream exiting separator 17 in Figure 3 is introduced into reactor 18 of Figure 3 at temperatures in the range of about 40 ° C (104 ° F) to 80 ° C. (176 ° F) and at a pressure in the range of about 140 kPa (20 PSI) to 350 kPa (50 PSI). Water is simultaneously introduced into reactor 18 at a temperature in the range of about 40 ° C (104 ° F) to 80 ° C (176 ° F) and at a pressure in the range of about 140 kPa (20 PSI) to 350kPa ( 50 PSI). The residence time in this reactor is in the range of about 20 seconds to 60 seconds, preferably 15 seconds to 30 seconds. This step is added to wash the aromatics stream with water, thereby polishing off any residual caustic from the aromatic hydrocarbon stream. The raffinate from separator 17 in the Figure is sodium sulfite.

[0246] The substantially water-free aromatics stream exiting reactor 18 is then introduced into separator 19 in Figure 3, where residual water is removed thereby producing ultra-low sulfur aromatics and low sodium sulfite raffinate. concentration. Water-washed aromatic hydrocarbon has uses in multiple industrial applications, known to those skilled in the art. Most importantly, there is a very low loss of valuable aromatic hydrocarbons and the sulfur is not in the form of highly available elemental sulfur, but in a sodium sulfite solution, which could be dehydrated if necessary.

[0247] If particular locations do not present onerous limitations on Total Aromatics or PAHs or both, the sulfur-free aromatics can be mixed back into the Ultra Low Sulfur Content Hydrocarbon stream that exits columns 10 and 11 of adsorption of Figure 3.

Figures 4-6

[0248] The present invention will now be further described by way of preferred embodiments which are described below with reference to the third aspect and Figure 4-6, and which are intended to be illustrative only and not restrictive.

[0249] Figure 4-6 shows a general schematic for an embodiment of the process disclosed herein in accordance with the third aspect. This embodiment is for a process intended to desulfurize a Transmix / Diesel feed (fractionated transmix feed diesel), which is hereinafter referred to as HS Diesel. Figures 4-6 detail a three-stage processing facility: i) Figure 4 details a feed preparation stage, ii) Figure 5 details an oxidation stage and iii) Figure 6 details a separation stage and adsorption. Such a three-stage facility can process 1,500 B / day (63,000 gallons / day).

[0250] Figure 4 details feed preparation for feedstock (HS diesel), oxidant (H2O2), PTA (phosphotungstic acid), PTC (Ultra C from Ultraclean) and acetonitrile.

[0251] The gas oil feedstock to be desulphurized (Gas oil HS) is supplied from a storage tank (1). It is strained through a duplex strainer type filter (2) and filtered through a vortex filter (3) before pumping it into a HS diesel storage tank (4) (approximately 3785.4 liters (100Gal)). From the storage tank (4) it is pumped as required to provide feed (5) of Diesel HS (diesel containing sulfur) to the next stage as detailed in Figure 5.

[0252] The oxidant is stored in a storage tank (approx. 11356.2 liters (3000 Gal)) (8) and pumped into a metered oxidant feed tank (approx. 378.5 liters (100 Gal)) (9). From the metered feed tank (9) the oxidant is pumped as required to provide feed (10) of oxidant to the next stage as detailed in Figure 5.

[0253] The PTC is stored in the PTC storage tank (approx. 1892.7 liters (500 Gal)) (11) to which recycled PTC from the diesel / water coalescer (25) is supplied as shown in Figure 5. The PTC is pumped into a metered PTC feed reservoir (approximately 378.5 liters (100 Gal)) (12). From the metered PTC feed tank (12), the PTC is pumped as required to provide PTC feed (13) to the next stage as detailed in Figure 5.

[0254] The PTA is stored in a PTA storage tank (approx. 1892,7 liters (500 Gal)) (14) and is supplied recycled PTA from the water / water evaporator (28) with PTA as shown in Figure 5. It is pumped into a metered PTA feed tank (approx. 378.5 liters (100 Gal)) (15). From the dosed PTA feed tank (15) the PTA is pumped as required to provide PTA feed (16) to the next stage as detailed in Figure 5.

[0255] Acetonitrile is stored in a bulk storage tank (approx. 18927.1 liters (5000 Gal)) (17) and fed as required to provide feed (18) of acetonitrile which is then available as feed of acetonitrile for the next stage as detailed in Figure 6, where it is strained and pumped to a smaller storage tank.

[0256] Several valves (including safety shut-off valves and safety isolation valves) (6), pumps (7) and LIT's, PIT's, DPIT's and AIT's can be positioned along each feed preparation path, according to required.

[0257] Figure 5 details the oxidation stage of the process. The HS Diesel Oil (5) is heated by an electric circulation heater (19) in combination with a brazed plate heat exchanger (20) to a temperature in the range of approximately 30 ° C (86 ° F) to 65 ° C (149 ° F) and at a pressure in the range of about 140 kPa (20 PSI) to 350 kPa (50 PSI). Dosed amounts of oxidant (10) (H2O2), PTC (13) (UltraC) and PTA (16) (Phosphotungstic acid) are combined with the heated HS Diesel (5) in a pipe mixer (21), and are introduced to the same time and at a temperature preferably in the range of about 20 ° C (68 ° F) to 30 ° C (86 ° F), in the oxidation Reactor 1 (22). The amount of oxidant introduced is metered proportionally with an equivalent ratio of 2 moles to 4 moles of oxidant with respect to 1 mole of sulfur. This oxidant is sufficient to oxidize the sulfur compounds of the hydrocarbon feedstock to sulfoxides and / or sulfones. The oxidation mixture resulting from Oxidation Reactor 1 (22) is then fed to Oxidation Reactor 2 (23), and optionally combined with a fresh supply of H2O2, to complete the oxidation of sulfur in the HS gas oil.

[0258] The resulting oxidized gas oil leaving the oxidation Reactor 2 (23) is filtered (24) and fed to a gas oil / water coalescer (25) where the oxidized gas oil (30) is separated from the aqueous phase containing PTA and PTC. The use of a separator (coalescer) is required to remove the water formed from the decomposition of hydrogen peroxide (approximately 67-70% of the mass of the added hydrogen peroxide). This results in "dry" diesel containing <20 ppm of water. The PTC is separated from the water and the PTA by a tubular centrifuge (26), and is pumped to the PTC storage tank (11) for reuse. The water and the PTA are stored in a water storage tank (27) and are fed to a Water / Water Evaporator (28) with PTA for the separation of the PTA that is also recycled and pumped to the tank (14) of PTA storage for reuse.

[0259] The oxidized gas oil solution (containing sulfone) is stored in an oxidized gas oil storage tank (29) and is available to be pumped (7) in order to supply oxidized gas oil (30) for the next stage as detailed in Figure 6.

[0260] Any excess heated diesel oil (44), after heating of (20) and (19), can be fed and stored in the HS diesel storage tank (4) as detailed in Figure 4. Specifically, In one embodiment, the hot diesel (at approximately 60 ° C or 140 ° F) passes through the heat exchanger (20) to preheat the incoming cold HS diesel to approximately 50 ° C before reaching the circulation heater (19) electric. This heater then heats the diesel to between 60 ° C and 65 ° C before entering the oxidation process. In addition to using waste heat for efficiency reasons, the temperature of the oxidized diesel leaving the The heat exchanger is reduced to approximately 30 ° C before being stored in the oxidized diesel storage tank (29).

[0261] Various valves (including safety shut-off valves and safety isolation valves) (6), pumps (7) and LIT's, PIT's, DPIT's and AIT's can be positioned along each path as required.

[0262] Figure 6 details the process separation and adsorption steps. The oxidized gas oil (30) is pumped from the oxidized gas oil storage tank (29). Sulfones are extracted from oxidized gas oil using liquid / liquid extraction with the use of acetonitrile as the extractant. The acetonitrile (18) is supplied from the storage tank (17) and is strained in a filter (2a) of the duplex strainer type before being stored in the acetonitrile storage tank (31). The acetonitrile is pumped from the storage tank (31) and combines with the oxidized gas oil (30). The acetonitrile (18) and the oxidized gas oil (30) are then mixed through a pipe mixer (32) and an in-line built-in static mixer (33) and then fed into a separator (34). It will be appreciated that the separator can be any known separator such as coalescing or centrifugal or electrostatic type. In this embodiment, the sulfone-loaded acetonitrile is separated from the gas oil by a primary gas oil / acetonitrile coalescer (34). The resulting gas oil stream is further extracted with acetonitrile (18) - again the acetonitrile is combined with the gas oil stream and mixed in a pipeline mixer (35) followed by an in-line built-in static mixer (36). The acetonitrile (containing any residual sulfones) is separated from the gas oil by a secondary gas oil / acetonitrile coalescer (37).

[0263] The sulfone is separated from the separated acetonitrile by a centrifuge (38) and the acetonitrile is recycled and returned to the acetonitrile storage tank (31) for later use. The separated sulfones are stored in a sulfone storage tank (39) for waste collection. Alternatively, the separated sulfones are subjected to tertiary oxidation (described hereinbefore) before or after a "buffing" step. If tertiary oxidation of the resulting sulfones is deemed necessary, as a result of higher sulfur concentrations and / or larger amounts of feedstock, then the sulfone stream is fed to an Oxidation Reactor and combined with sodium hydroxide (approximately 45%) at about 75 ° C for about 8 minutes to allow complete or near complete oxidation of the sulfone component to sodium sulfite. The sulfur-free (or low-sulfur) aromatic hydrocarbons resulting from this reaction are fed into a separator where the aromatic hydrocarbon components are separated from the sodium sulfite solution. This separator can be of the coalescing or centrifugal or electrostatic type. The tertiary oxidation methodology described in relation to Figures 2 and / or 3 can be adopted.

[0264] The substantially sulfur-free gas oil exiting the secondary coalescer (37) is then subjected to a "polishing" step. As has been broadly stated above, the polishing stage consists of two columns (40 and 41) loaded with adsorbent, although this number of columns can be substantially increased depending on the performance of the diesel oil to be polished. One column, or group of columns, is in "adsorption" mode while the other is in "desorption" mode. In adsorption mode, the sulfur-free gas oil is directed to the column currently designated as adsorption mode, which is loaded with media consisting of an adsorbent known to those skilled in the art. Consequently, the substantially sulfur-free diesel stream exiting the diesel / ACN secondary coalescer (37) is pumped to adsorption columns 1 (40) and 2 (41) where any remaining sulfones or water are removed using a " adsorbent "on a column. Any of the absorbents mentioned above can be used. In this embodiment, the adsorbent "Attapugite" (or Fuller's Earth) is used and is readily available in Georgia, USA.

[0265] The gas oil leaving the adsorption column (40 and 41) is an ultra-low sulfur (ULS) gas oil and this is stored in a ready-to-use ULS gas oil storage tank (42). There is the possibility that out-of-specification diesel that comes out of the storage tank (42) will separate (43) and feed to the HS storage tank (4) as detailed in Figure 4. The diesel that is sent from the columns (40 and 41) of adsorption mentioned above to the ULSD storage tank (42) can either be sent to the customer's main ULSD storage tank or it can be redirected back to the HS diesel storage tank (4). Drift control is achieved by monitoring the total sulfur level and when this level exceeds 10 ppm, an automatic control system considers the diesel to be "out of specification", at which point the out of specification diesel is rejected and shipped. back to the HS diesel storage tank for reprocessing.

[0266] Several valves (including safety shut-off valves and safety isolation valves) (6), pumps (7) and LIT's, PIT's, DPIT's and AIT's can be positioned along each path as required.

[0267] Tables 10 and 11 show reductions in sulfur level for the desulfurization process described above.

Examples: sulfur analysis

[0268] Natural Gas Condensates (NGC), high sulfur diesel hydrocarbons, jet fuel for turbines and Transmix / Diesel streams were reacted with an oxidant and their sulfur content was examined before and after the process of oxidation. The initial and final sulfur content (before and after the oxidation process) was determined using a sulfur sensitive X-Ray Fluorescence (XRF) detector / analyzer. Independent comparative samples were submitted to SGS (Society Generale De Surveillance) for total sulfur measurement and identification of sulfur compounds using GC (Gas Chromatography) and SCD (Sulfur Chemiluminescence Detection). SGS and in-house laboratory measurements hold up the comparison favorably. Sulfur levels were measured using international ASTM methods (eg ASTM D5623 and D5453).

[0269] It will be appreciated that any other known methods can be used to measure the content of S.

[0270] Results are provided in Tables 1 to 11.

Example 1 - Natural gas condensates (NGC)

a) Molecular oxygen as oxidant

[0271] The sulfur species in the Natural Gas Condensate (NGC) source were electron dense and therefore easily oxidized. Consequently, no active catalyst / cocatalyst was required. The oxidant used was molecular oxygen. The oxidation mechanism emulates that of oxidation using primary or secondary oxidants or a combination thereof: this is a transfer of electrons from sulfur that are taken up by oxygen, thus producing sulfones. Actual SGS (Society Generale De Surveillance) results recorded using NGC were obtained using molecular oxygen as oxidant followed by IL / water extraction and hydrocarbon wash / polish techniques with water as described below. The source of the oxygen was 99% pure bottled oxygen. The IL used is triisobutyl (methyl) phosphonium tosylate.

[0272] A 5 gallon (18.9 liter) sample of NGC was circulated from a 7 gallon (26.5 liter) heating reactor through an eductor to a series of 3 in-line built-in static mixers. These mixers, although not as effective as the countercurrent stirred column type reactor, served to mix the gas (oxygen) phase with the liquid NGC phase. Mixing kinetics were not expected to emulate that of the reactor; therefore, the residence time was approximately 65 minutes. The NGC was returned to the reactor through the static mixers.

[0273] The NGC was circulated under pressure at approximately 2.1034 kPa (150 psi) and slowly heated over a period of 20 minutes until the NGC reached a temperature of approximately 65 ° C (149 ° F). When this temperature was reached, an oxygen feed of approximately 95% purity was supplied to the eductor. The feed was dosed such that an amount of approximately 3 times the stoichiometric requirement was injected during the time of oxidation. The oxygen was expelled at a rate that was approximately 50% of the feed rate. This expulsion also allowed for sufficient differential pressure over the eductor, thus maintaining sufficient velocity through the static mixers to promote optimal two-phase mixing.

[0274] At the end of the oxidation phase, the NGC was allowed to cool to approximately 40 ° C (104 ° F). Approximately 100 ml of IL was heated to approximately 40 ° C (104 ° F) and added to a 250 ml sample of NGC. The contents were thoroughly mixed with a shaker for approximately 1 minute and allowed to settle under gravity. During this period, a small amount of NGC was vaporized but the IL had been thoroughly mixed and it was assumed that the oxidized sulfur compounds would be absorbed into the IL.

[0275] A sample of the NGC was removed from the two-phase solution and it was then added to a separation vessel. An equal amount of water was added to the NGC in the container. The water was at approximately 35 ° C (95 ° F) and this NGC / water mixture was thoroughly stirred for one minute. The mixture was allowed to separate by gravity for approximately 2 minutes, after which the NGC was removed to a new container. An equivalent amount of water was added to the NGC and mixed according to the first water wash. The treated NGC was bottled and shipped for total sulfur measurement and identification of sulfur compounds.

[0276] It was then assumed that (i) the sulfur in the NGC raw material would have been converted to sulfoxide and / or sulfone and (ii) that these oxidized compounds, upon contact with IL, preferentially migrate to the phase IL from the biphasic system and (iii) any residual IL would have been separated from the NGC such that sulfur compounds would be removed from the NGC.

[0277] The IL used in the extraction process was loaded with some organic matter which was considered to be aromatic sulfur oxidation products, as the IL had darkened and after the addition of water heated to 40 ° C (104 ° F) and vigorous stirring, an organic layer containing sulfur separated after approximately 30 seconds, from completion of stirring.

b) H ² O ² catalyzed as oxidant

[0278] The replacement of the oxidant used in point a) above by catalyzed hydrogen peroxide achieved the same result. Hydrogen peroxide when catalyzed with a controlled rate control catalyst, such as the combination of sodium tungstate dihydrate and phosphoric acid (phosphotungstic acid), decomposes into OH / singlet oxygen radical. Only the electron-rich sulfur species were present in this very low-boiling raw material (36 ° C) and consequently only a primary oxidant was used. Oxidation was accomplished using decomposing hydrogen peroxide and concurrent PTC was not required due to the electron dense sulfur species mentioned above. It is also assumed that the very light condensate was easily oxidized with the oxidant and the catalyst without the PTC, since in most cases, during the oxidation process, it was possible that the hydrocarbon was in the gas phase, thus phase transfer became a non-dominant factor compared to its essential requirement when oxidizing hydrocarbon streams heavier than at the normal temperature of the oxidation process it is always in the liquid phase. This, as well as the easy oxidation of the sulfur species, seems to be the reason why the oxidant mentioned above alone was sufficient to oxidize the sulfur compounds present.

[0279] The same protocol and test equipment as used in point a) was used.

[0280] A 5 gallon (18.9 liter) sample of NGC was circulated from a 7 gallon (26.5 liter) heating reactor through an eductor to a series of 3 in-line built-in static mixers. These mixers, although not as effective as the countercurrent stirred column type reactor, served to mix the aqueous oxidant, which was hydrogen peroxide at a concentration of 30%, together with the decomposition moderating catalyst sodium tungstate dihydrate and the acid. Reagent grade phosphoric, with the liquid phase of NGC. Mixing kinetics were not expected to emulate that of the reactor; therefore, the residence time was approximately 80 minutes. The NGC was returned to the reactor through the static mixers.

[0281] The NGC was circulated under pressure at approximately 689.48 kPa (100 psi) and slowly heated over a period of 20 minutes until the NGC reached a temperature of approximately 65 ° C (149 ° F). When this temperature was reached, the aqueous hydrogen peroxide was fed through a needle throttle valve to the venturi eductor. The feed was dosed such that an amount of approximately 2.5 times the stoichiometric requirement was injected during the initial 2 minute oxidation period and then again after a 20 minute elapsed time for an additional 2 minute period. The recipe for the experiment was as follows:

- Hydrogen peroxide at a concentration of 30% = 120 mls

- Sodium tungstate dihydrate in solution (miscible with water at approximately 1: 1.1) = 4.5 mls

- Reagent grade phosphoric acid = 0.9 mls

[0282] Upon completion of the oxidation phase, the NGC was allowed to cool to approximately 40 ° C (104 ° F). Approximately 100 ml of IL was heated to approximately 40 ° C (104 ° F) and added to a 250 ml sample of NGC. The contents were thoroughly mixed with a shaker for approximately 1 minute and allowed to settle under gravity. During this period, a small amount of NGC was vaporized but the IL had been thoroughly mixed and it was assumed that the oxidized sulfur compounds would be absorbed into the IL just like the water resulting from the decomposition of hydrogen peroxide.

[0283] A sample of NGC was removed from the two-phase solution and then added to a separation vessel. An equal amount of water was added to the NGC in the container. The water was at approximately 35 ° C (95 ° F) and this NGC / water mixture was thoroughly stirred for one minute. The mixture was allowed to separate by gravity for approximately 2 minutes, after which the NGC was removed to a new container. An equivalent amount of water was added to the NGC and mixed according to the first water wash.

[0284] It was then assumed that (i) the sulfur in the NGC raw material would have been converted to sulfoxide and / or sulfone and (ii) that these oxidized compounds, upon contact with IL, preferentially migrate to the phase IL from the biphasic system and (iii) any residual IL would have been separated from the NGC such that sulfur compounds would be removed from the NGC.

[0285] The IL used in the extraction process was loaded with some organic matter that was assumed to be aromatic sulfur oxidation products, since the IL had darkened and after the addition of water heated to 40 ° C ( 104F) and vigorous stirring, an organic layer containing sulfur separated after about 30 seconds, from the completion of the stirring. The treated NGC was subsequently centrifuged, after which it was tested on a Spectro 2000 XRF total sulfur analyzer. This analysis detected 9.8 ppm sulfur. This sample was not independently verified by SGS laboratories, therefore no verification data is provided. The test was performed to compare the efficiency differential between catalyzed hydrogen peroxide and molecular oxygen. It was assumed that, at the time of testing, due to the nature of the sulfur compounds and the expected NGC in the gas phase, both combinations of oxidants would work and that PTC would not be required.

[0286] The test results for Example 1 are provided in Tables 1 to 3. Table 1 provides a breakdown into components and Table 2 provides a feedstock analysis (speciation and total sulfur) while Table 3 shows results of treated NGC.

[0287] This example demonstrates that the sulfur in NGC is relatively easily oxidized due to which the inventor believes that they are the lower molecular weight sulfur compounds having the most electron-dense species. Higher boiling point sulfur compounds are known to migrate to higher MW streams, such as diesel, and these species are more resistant to oxidation. Due to the relative ease of sulfur oxidation in NGC, PTC was not required to influence the quantitative oxidation of sulfur. However, it is believed that PTC would have helped, but is not absolutely necessary in the case of sulfur oxidation in the lighter fraction hydrocarbon. The process disclosed herein is intended to cover sulfur removal from more complex sulfur-containing hydrocarbon materials.

Example 2: Transmix diesel hydrocarbon (H ² O ² catalyzed and cocatalyzed)

[0288] A 3 gallon sample of transmix hydrocarbon was circulated through a controlled cavitation mixing reactor which induced heating internally in the reactor. The raw material at room temperature was circulated for approximately 3 minutes, which caused a temperature rise from 20 ° C (68 ° F) ambient to 70 ° C (158 ° F). When the temperature of the hydrocarbon reached 65-70 ° C, catalyzed and cocatalyzed hydrogen peroxide (hydrogen peroxide and phosphotungstic acid and PTC Ultra C) was introduced through an eductor through which the hydrocarbon flowed at a pressure of about 138 kPa (20 psi). After applying the oxidant (catalyzed and cocatalyzed hydrogen peroxide) to the hydrocarbon through a Venturi and a needle regulating valve, the resulting hydrocarbon / oxidant was fed to a static, in-line, motorized mixer directly at the diesel inlet. of the access of the mixer reactor incorporated in line.

[0289] The mixed hydrocarbon was circulated through a holding tank by being reacted with the oxidant at an approximately twice stoichiometric ratio based on the sulfur content (molar) in the hydrocarbon feedstock.

[0290] The hydrocarbon was circulated through the system for a period of time of 60 minutes, which was equivalent to a cumulative residence time of 5 minutes in a typically used countercurrent reactor. Samples were taken at scheduled intervals, although the sample taken at the end of the aforementioned 60 minute period was subjected to the IL extraction procedure and the water wash / polish procedure as described in the procedure for desulfurizing NGC.

[0291] After the IL extraction and water wash / polish procedure, a sample was taken and analyzed using a Spectro XRF (X-Ray Fluorescence) laboratory analyzer. A separate comparative sample was sent to SGS (Society Generale De Surveillance) for a total sulfur measurement and identification of sulfur compounds. SGS and internal laboratory measurements held up the comparison favorably, with internal ones (analysis by Spectro XRF) measuring about 5 ppm more than SGS data.

[0292] Test results for this Transmix hydrocarbon feedstock and Transmix desulfurized hydrocarbons are provided in Tables 4 and 5.

Example 2a: Transmix diesel hydrocarbon (H ² O ² catalyzed and cocatalyzed)

[0293] A 3 gallon sample of transmix hydrocarbon was circulated through a cavitation controlled mixing reactor which induced heating internally in the reactor. The raw material at room temperature was circulated for approximately 3 minutes, which caused a temperature rise from 20 ° C (68 ° F) ambient to 70 ° C (158 ° F). When the temperature of the hydrocarbon reached 65 - 70 ° C, catalyzed and cocatalyzed hydrogen peroxide (hydrogen peroxide and phosphotungstic acid and PTC Ultra C) was introduced through an eductor through which the hydrocarbon flowed at a pressure of approximately 138 kPa (20 psi). After applying the oxidant (catalyzed and cocatalyzed hydrogen peroxide) to the hydrocarbon through a Venturi and a needle regulating valve, the resulting hydrocarbon / oxidant was fed to a static, in-line, motorized mixer directly at the diesel inlet. of the access of the mixer reactor incorporated in line.

[0294] The mixed hydrocarbon was circulated through a holding tank by being reacted with the oxidant at an approximately twice stoichiometric ratio based on the sulfur content (molar) in the hydrocarbon feedstock.

[0295] The hydrocarbon was circulated through the system for a time period of 60 minutes, which was equivalent to a cumulative residence time of 5 minutes in a typically used countercurrent reactor. Samples were taken at scheduled intervals, although the sample taken at the end of the 60 minute period mentioned above was subjected to the liquid / liquid extraction procedure with acetonitrile and the water wash / polish procedure as described in the procedure for desulfurizing NGC. .

[0296] After the polishing and acetonitrile extraction procedure, a sample was taken and analyzed using a Spectro XRF (X-Ray Fluorescence) laboratory analyzer. A separate comparative sample was sent to SGS (Society Generale de Surveillance) for a total sulfur measurement and identification of sulfur compounds. SGS and internal laboratory measurements held up the comparison favorably, with internal ones (analysis by Spectro XRF) measuring about 5 ppm more than SGS data.

[0297] The test results of this raw material for Transmix hydrocarbons and desulfurized Transmix hydrocarbons were the same as those provided in Tables 4 and 5.

Example 3: Hydrocarbons from refinery diesel

[0298] A 3 gallon sample of refinery hydrocarbons was treated. The procedure and methodology and equipment used were identical to those described in the description of Transmix hydrocarbons mentioned above in Example 2.

[0299] Test results for this refinery hydrocarbon feedstock and desulfurized refinery hydrocarbons are provided in Tables 6 and 7.

Example 4: Jet fuel for turbines

[0300] A 3 gallon (11.4 liter) turbine jet fuel sample was treated. The procedure and methodology and equipment used were identical to those described in the description of Transmix hydrocarbons mentioned above in Example 2. The test results of this aviation turbine fuel and aviation turbine fuel desulfurized are provided in Tables 8 and 9. Example 5: Realization according to Figures 4-6

[0301] A process for desulfurizing a Transmix / Diesel feed (fractionated transmix feed diesel) has been described hereinabove, referring to Figures 4-6. SGS (identification of sulfur compounds by GC and SCD) provided an analysis of total sulfur content. The sulfur analysis for the Transmix / Diesel feed before undergoing the process is shown in Table 10. The sulfur analysis for the desulfurized ULS diesel after the completion of the process is shown in Table 11. Therefore, the process described in Figures 4-6 successfully reduced the sulfur content of the transmix / diesel feed from 271 ppm to 0 ppm according to ASTM D5623 and from 334 ppm to 2 ppm according to ASTM D5453.

Results

[0302]

-

-

T l: N - D lf r - nlii zfr - m r 2

T l 4: M ri Prim Hir r r l Tr nmix - nlii zfr

T l: Hi r r r l Tr nmix - lf r - nlii zfr

T l: M ri Prim Hi r r r l Rfinrí - nlii zfr

T l 7: Hi r r r l Rfinrí - lf r - nlii zfr

-

- -

T l 1: M ri Prim l Tr nmix - nlii zfr

T l 11: M ri Prim l Tr nmix - lf r - nlii zfr

Arguing the test results

[0303] Natural Gas condensate containing a total S level of 432 ppm (Table 2) was successfully desulfurized to a total S level of 4.8 ppm (see Table 3). The kinetics of the reaction can be optimized and differs according to the oxidation reactor used for said oxidation reaction. It is empirically proven that the residence time of the Multistage Stirred Column is similar to the emulation using Static Mixers, which are both substantially different from the aforementioned options of Cavitation or Film Shear Reactors. The reaction requires less residence time in these PI type reactors (process intensification), mainly due to higher mass transfer.

[0304] Transmix gas oil hydrocarbon containing a total S level of 407 ppm (see Table 4) was successfully desulfurized to a total S level of 9.2 ppm (see Table 5). The kinetics of the reaction resembles the residence time and mass transfer mentioned above according to the Natural Gas Condensate.

[0305] Refinery gas oil hydrocarbon containing a total S level of 3996 ppm (Table 6) was successfully desulfurized to a total S level of 10 ppm (Table 7). The kinetics of the reaction resembles the residence time and mass transfer mentioned above according to the Natural Gas Condensate.

[0306] Turbine jet fuel containing a total S level of 1518 ppm (Table 8) was successfully desulfurized to a total S level of 9 ppm (Table 9). The kinetics of the reaction resembles the residence time and mass transfer mentioned above according to the Natural Gas Condensate.

[0307] Transmix / diesel feed (Example 5) containing a total S level of 271 ppm (Table 10) was successfully desulfurized to a total level of 0 ppm (Table 11) in accordance with ASTM D5623 and de 334 ppm (Table 10) to 2 ppm (Table 11) according to ASTM D5453 standards.

[0308] Those skilled in the art will appreciate that numerous variations and / or modifications can be applied as shown in the specific embodiments without departing from the scope of the invention as defined in the claims. Therefore, the present embodiments are to be considered in all respects as illustrative and not restrictive.

Claims (20)

1. Process for reducing the sulfur content of a hydrocarbon material containing sulfur compounds, the process comprising: a) contacting the hydrocarbon material with one or more primary oxidants to provide a primary oxidized hydrocarbon material such that the primary oxidant oxidizes sulfur compounds to sulfoxide and / or sulfone compounds, wherein the primary oxidant is selected from one or more of the group consisting of N-chloroimide, hypobromous acid, electrolyzed oxidant water, and catalyzed and cocatalyzed hydrogen peroxide; Y b) contacting the primary oxidized hydrocarbon material with a secondary oxidant to provide a secondary oxidized hydrocarbon material, wherein the secondary oxidant is selected from one or more of the group consisting of hydroxyl radicals, liquid ferrate (iron VI ), chlorine dioxide and hypofluorous acid / polar liquid solvent, such that the secondary oxidant oxidizes sulfur compounds to sulfoxide and / or sulfone compounds; Y c) contacting the primary and secondary oxidized hydrocarbon material with an extractant to allow at least a portion of the sulfoxide and / or sulfone compounds to be extracted into the extractant in order to provide a stream of sulfoxide and / or or sulfone and a low sulfur hydrocarbon stream; and d) contacting the sulfoxide and / or sulfone stream with a tertiary oxidant to provide an aqueous sulfite stream and a low-sulfur aromatic hydrocarbon stream, wherein the tertiary oxidant oxidizes sulfone and / or sulfoxide compounds to compounds. sulfite; Y e) separating the sulfoxide and / or sulfone stream from the low sulfur hydrocarbon stream, and when the primary oxidant is catalyzed and cocatalyzed hydrogen peroxide, it is hydrogen peroxide catalyzed by homogeneous or heterogeneous catalysts. Process according to claim 1, wherein the primary oxidant is hydrogen peroxide catalyzed by homogeneous or heterogeneous catalysts, including catalysts selected from the group including transition metals, noble metals, and degradation rate control catalysts; and cocatalyzed by a Phase Transfer Catalyst (PTC), preferably where the catalyst is phosphotungstic acid or a heterogeneous catalyst, furthermore preferably wherein the PTC is a quaternary ammonium salt, still more preferably wherein the quaternary ammonium salt is selected from the group consisting of quaternary ammonium hydrogen sulfates; methyltrialkyl (C8-Cii) ammonium chloride; and N-Methyl-N, N-dioctyloctane-1-ammonium salts, still more preferably wherein the quaternary ammonium hydrogen sulfate is a tri-C8-10alkylmethyl, hydrogen sulfate. 3. Process according to claim 1, wherein the extractant is a polar extraction solvent selected from the group consisting of acetonitrile, DMF, DMSO, methanol, water, brine and furfural or an ionic liquid (IL), preferably wherein the extractant is acetonitrile. A process according to claim 1, wherein the hydrocarbon material containing sulfur compounds has a sulfur mass greater than 1000 ppm. Process according to claim 1, in which the primary oxidant is N-chloroimide, preferably wherein the N-chloroimide is prepared by reaction of sodium hypochlorite, water and an imide, further preferably i) in which the imide is cyanuric acid, and / or ii) in which N-chloroimide is prepared in situ. Process according to claim 1, in which the primary oxidant is hypobromous acid, preferably in which the hypobromous acid is prepared in situ by electrolysis of hydrogen bromide in water. Process according to claim 1, in which the primary oxidant is electrolyzed oxidant water. 8. Process according to claim 1, wherein the hydrocarbon material is brought into contact with the primary oxidant in at least a stoichiometric amount for the conversion of sulfur compounds to sulfoxide and / or sulfone compounds. Process according to claim 1, wherein the secondary oxidant is brought into contact with the primary oxidized hydrocarbon material or the hydrocarbon material at a temperature below 35 ° C, and at a pressure below 700 kPa, and during a period of time in the range of 30 seconds to 10 minutes. Process according to claim 1, in which the secondary oxidant is chlorine dioxide, in the form of a solution in stabilized water having a chlorine dioxide content in the range of 3000 ppm (0.3%) to 8000 ppm. (0.8%). Process according to claim 1, in which the secondary oxidant is hypofluoro acid in acetonitrile, prepared by bubbling a gaseous mixture comprising fluorine and nitrogen in liquid acetonitrile to form HOF.CH3CN, wherein the concentration of mixed fluorine ( mixed) with nitrogen does not exceed 20% by weight of fluorine blended with nitrogen. 12. The process of claim 1, wherein the extractant is a polar extraction solvent selected from the group consisting of acetonitrile, DMF, DMSO, methanol, water, brine, and furfural or an ionic liquid (IL). The process of claim 1, wherein a liquid / liquid extraction or ion exchange adsorption process is used to extract the sulfone / sulfoxide compounds. Process according to claim 1, in which the primary and / or secondary oxidized hydrocarbon material obtained from step a) and / or step c) is washed with water. 15. Process according to claim 1, wherein the tertiary oxidant is a caustic solution, selected from the group consisting of: i) sodium hydroxide, ii) potassium hydroxide and iii) hydroxyl radicals. 16. Process according to claim 1, in which the tertiary oxidant is sodium hydroxide and an aqueous sodium sulphite solution is formed, preferably in which the sodium hydroxide solution is in a concentration of 30-60%. 17. Process according to claim 16, in which the tertiary oxidant is hydroxyl radicals such that after the addition of water, sulfuric acid is formed, preferably in which the stoichiometric ratio of hydroxyl radicals to sulfone / sulfoxide is in the range from 1: 1 to 4: 1. 18. Process according to any one of claims 1 to 17, wherein the low sulfur hydrocarbon stream and the low sulfur aromatic compound are combined and recycled as low sulfur hydrocarbon fuel. 19. Process according to claim 1, wherein the primary oxidant is catalyzed and cocatalyzed hydrogen peroxide and wherein the catalyzed and cocatalyzed hydrogen peroxide is phosphotungstic acid catalyzed hydrogen peroxide or a heterogeneous and cocatalyzed catalyst with a phase transfer catalyst (PTC) comprising a quaternary ammonium salt; Y in which the process further comprises: f) contacting the low sulfur hydrocarbon stream obtained in step c) with an adsorbent to remove residual sulfur compounds from the low sulfur hydrocarbon stream (LSD) in order to provide a hydrocarbon stream containing ultra-low sulfur (ULSD), preferably i) in which the adsorbent is selected from physical or physicochemical adsorbents, zeolite Y, activated carbon and Metal Oxide Structures (MOF), or ii) wherein, after step f), the loaded absorbent is regenerated / purged using N2 disaggregation by heating to desorb sulfur compounds from the adsorbent. 20. Process according to claim 1, wherein the low sulfur hydrocarbon (LSD) stream is polished using adsorbents including MOF (Organic Metal Structures), (C1sH6Cu3O12) - Copper Benzene-1,3,5-Tricarboxylate, group of adsorbents of the type Metal Oxide Purification Adsorbent, CuChMIL-47 MOF, Zeolite Y, Molecular Impression Chitosan or Activated Carbon.